Updates: [live updates have concluded as of 5:50 pm EST, a list of updating resources are sourced at the bottom of this post]

5:48 pm - In Brief: Police have arrested a 32 year old Norwegian man who is being linked to both the downtown Oslo bombing of the government building that houses Prime Minster Jens Stoltenberg's office and the shootings at a youth meeting on the nearby Utoya Island. The attacks combined have currently left at least 16 or 17 people dead and over a dozen injured. U.S. officials cited by CNN say that they haven't seen evidence that this had "hallmarks of a big sophisticated attack." Reuters published a list of likely suspects of groups/individuals behind the attack. In remarks on the attack, Prime Minister Stoltenberg said: "No one can bomb us to be quiet. No one can shoot us to be quiet no one can ever scare us from being Norway." Rescue workers are shown at the site of the bombing in this Reuters photograph:

5:25 pm EST- Sky News is reporting that Norwegian Police say there are "undetonated explosives found on Utoya Island," the site of the shootings near Oslo.

4:55 - BBC News relays that the "justice minister has just confirmed the suspect arrested today at the youth camp in [Utoya Island] was Norwegian." A New York Times headline updates the combined death toll to at least 16 from the bombing and shooting. Reuters reports the number as 17 dead.

4:53 pm EST - AFP photographer Roald Berit captures firefighters working at the scene of the bombing in the aftermath:

4:45 - Norwegian Prime Minister Jens Stoltenberg's remarks on the attacks, via The Telegraph:

I have message to the person who attacked us and the people who are behind it: You're not going to destroy us. You're not destroying our democracy and our work for a better world. We're a small country but a very proud country. No one can bomb us to be quiet. No one can shoot us to be quiet no one can ever scare us from being Norway.

4:34 - From BBC News: "A terrorism expert tells the BBC that Ansar al-Jihad al-Alami, or the Helpers of the Global Jihad, a terror group that claimed responsibility for the explosion in Oslo, was not behind the attack." Previously, a New York Times story cited a terrorism expert who mentioned that the group claimed credit for the attack. But the paper also noted: "It is not uncommon for terrorist groups to advance claims of responsibility for high-profile attacks, only to have the claims prove to be spurious."

4:22 pm EST - The Guardian cites Norwegian TV network NRK to say that the Utoya Island gunman may not have been disguised in a police uniform:

According to David Berry, from the department of Political Studies at Swansea University, on NRK in the last few minutes they interviewed the head of police in Oslo and he stated that the gunman was NOT wearing a police uniform, rather a blue jumper which had a Norwegian police badge or sign on it. He also confirmed that the suspect had never worked for the police.

4:18 - An Associated Press photographer captured an additional angle of the building and debris in the aftermath:

4:11 pm EST - From BBC News: "Acting Police Chief Sveinung Sponheim in Oslo says the shooter had also been spotted in the capital prior to the explosions."

4:06 - Brief summary of reports we've seen so far: a large explosion hit government buildings housing the office of Prime Minister Jens Stoltenberg in downtown Oslo, Norway. The prime minister and his staff have been reported safe. Police currently say there are seven dead and over a dozen wounded. In what's been reported as a linked attack, a man disguised as a police officer had opened fire on a youth meeting on the nearby Utoya Island. Oslo police, according to Reuters, said there was "nine, perhaps 10 people, killed" in that shooting. The Associated Press cited a witness noting more than 20 bodies at the shooting.

3:42 - A Reuters Flash relays that "Oslo police say nine, perhaps 10 people, killed" in Utoya Island shooting.

3:38 - Via The Telegraph, UK Prime Minister David Cameron states: "We will work with Norway to hunt the murderers who did this." Previously, President Obama said: "It's a reminder that the entire international community holds a stake in preventing this kind of terror from occurring. We have to work cooperatively together both on intelligence and in terms of prevention of these kinds of horrible attacks."

3:28 pm EST - Rune Håkonsen, who works with Norwegian broadcasting corp, tweets images of what appear to be people swimming away from Utoya Island. The Guardian notes that Norwegian television is "showing images taken from a helicopter showing people swimming in the water off Utoya Island, presumably they threw themselves into the sea to get away from the gunman. An eyewitness has reported bodies of people who had been shot floating in the water." Updated (3:53 pm): From the Associated Press, an aerial view of Utoya Island on July 21:

3:05 - Reuters is now reporting that at least seven have been killed in the Oslo bombing. In the linked Utoya Island shooting, there have been only unconfirmed reports of the number killed, according to BBC News.

3:00 pm EST - MSNBC.com relays from NRK (Norwegian TV) that police are "saying they now suspect one or more bombs may be at the scene" at Utoya Island, where the shooting purportedly took place.

2:55 - The Telegraph relays that Norway police have "arrested the assailant, and we believe that he's connected to both the bombings in Oslo and the shootings" at the nearby Utoya Island. The Associated Press has a newsbreak from an eyewitness speaking to Norwegian TV: "he saw more than 20 bodies" at the shooting.

2:48 - From a Reuters photographer, rescue workers at the site of the downtown Oslo bombing at the government building. Previously, the BBC had reported that there was still injured people inside the building.

2:42 - Terrorism expert Will McCants, via The New York Times, translates the statement issued by the group, Helpers of the Global Jihad, which claims "the attack was a response to Norwegian forces' presence in Afghanistan and to unspecified insults to the Prophet Muhammad." From McCants' translation: "We have warned since the Stockholm raid of more operations. What you see is only the beginning, and there is more to come."

2:39 - The mayor of Oslo tells CNN that he believes the situation has stabilized, but is unsure if bombing was terror attack: "This situation is under control, but it's been a terrible day...Today we think about the people in all other parts of the world who have been in the same situation."

2:28 - From Google Translate, an account of the moments leading up to the shootings on Utoya Island, given to the Associated Press (in Norwegian) by a security guard stationed at the youth meeting. The shooter was previously described as a man disguised as a police officer:

"There comes a silver van. In it sits a police officer wearing a police uniform and bulletproof vest. He comes out of the car, and show identification. Says that he is sent to check the safety, it is routine during the terrorist attack. Everything looks good, and [he] is called a boat carrying him over to Utøya. It took a few minutes, we heard the shooting."

2:25 - Via USA Today, President Obama's response: "After a meeting with New Zealand Prime Minister John Key, Obama said the attacks are the latest reminder that the world has a common duty to stop terrorism."

2:04 - From the BBC, Oistein Mjarum, the head of communications at the Norwegian Red Cross: "We fear the worst but we have no confirmed details of casualties or the number of dead."

1:59 - Reuters, via the BBC, says soldiers "have taken up position around central Oslo."

1:52 - Contrary to previous reports that four people had been killed in the Utoya Island shootings near Oslo, Breaking News relays: "Oslo police say cannot confirm anyone was killed at Labour Party youth camp shooting; Norwegian TV reported several killed."

1:46 - The downtown Oslo bombing and the Utoya Island shootings are now being linked. From CNN: "Police tell Norweigian broadcaster they have reason to believe shootings at youth camp and explosion in Oslo are linked."

1:42 pm EST - Reuters, via Sky News, updates the death toll from the downtown Oslo bombing: 7 people killed. In the Utoya Island shootings (20 miles from Oslo), Sky News had previously noted that four had been killed.

1:38 - The U.S. State Department condemned the attacks and also offered assistance to Norwegian authorities, according to a spokesperson speaking with the AFP.

1:34 - The Guardian points to this video below, which is allegedly of the second, possible explosion in downtown Oslo: The Guardian now writes (updated 2:10 pm EST): "This post has been removed because the video appears to be fake (thanks to all who pointed this out)." The video was of a purported second explosion in downtown Oslo.

1:29 - The New York Times notes that Muslim leaders in Norway have responded quickly to deny any speculation they were involved in the attacks. "This is our homeland, this is my homeland; I condemn these attacks and the Islamic Council of Norway condemns these attacks, whoever is behind them," said Mehtab Afsar, Secretary General of Islamic Council of Norway.

1:19 pm EST - More on the Utoya Island shootings: BBC News is relaying from Norwegian TV that "one person has been arrested at the Labour Party" meeting. Previously, the gunman had been described by The Guardian as a man disguised as a police officer.

1:15 - It appears that a group has claimed responsibility for the Oslo bombing: "an unknown group called 'Helpers of the Global Jihad' have posted a message that this is only the beginning of the reaction to Norwegian periodicals publishing the Muhammed cartoons, according to Andrew Boyle, a journalist in Norway," The Guardian reports. Also flagging the group was The Telegraph.

1:06 - From the Utoya Island shooting 20 miles away from the downtown Oslo bombings: "Many people are injured," according to the Norwegian State broadcaster, NRK, cited by CNN.

12:51 -  Sky News writes that four people have been killed during shootings at ruling Labour party youth meeting on Utoya Island, Norway. Reuters relays from Norwegian TV that five were injured in the shooting. Previously, The Guardian had reported that a man disguised as a police officer was firing shots at this youth meeting. "Utoya Island is roughly 20 miles north-west of Oslo," explains The Telegraph.

12:36 - Summary of reports we've seen so far: a large explosion (possibly two) hit government office buildings housing Prime Minister Jens Stoltenberg in downtown Oslo, Norway. ABC News sources said it was due to a car bomb. The prime minister and his staff have been reported safe. The current casualty tally from police is two dead, 15 wounded. In the aftermath of the explosions there have been multiple reports of suspicious packages and shots being fired by a man disguised as a police officer at a youth meeting near Oslo. The live resources we're following include: Reuters, The Guardian, BBC News, CNN's This Just In, The Telegraph, and Breaking News. Live video can be found here.

12:21 - There's been multiple reports of shootings in the aftermath of the bombings. From BBC News, relaying Reuters: "Police say some shots have been fired at a youth meeting in Oslo." And The Guardian: "A man disguised as a police officer began shooting where prime minister Jens Stoltenberg was attending a Labour party conference at Utoya, Stoltenberg has just confirmed."

12:13 - Via Breaking News, the Associated Press reports from Oslo police that the "office of broadcaster TV2 has been sealed off because of suspicious package." The Guardian adds more: Police "are telling people to leave the centre of Oslo and warning there could be more explosions. They are also examining an unexploded package, although the location of the package is not clear."

12:09 - Citing the Associated Press, the BBC says that Oslo police report 15 injured in the bombing.

12:03 pm EST - Reuters has a new report on the likely suspects of the attack. On their list: al Qaeda, the Islamic movement of Uzbekistan, Al Shabaab, Tehrik-e-Taliban Pakistan and AQkim.

11:57 - BBC News confirms with Assistant Chief Constable Egil Vrekke of the Oslo Police that two people have died from the bombing and rescue operations are ongoing. The Guardian relays the latest official police statement: "There has been one or several powerful explosions in the government district in Oslo. So far, police cannot say anything about the scope of the damage, aside from that there's been one or several explosions."

11:55 - An Associated Press photographer captured victims being treated from a street view in the surrounding area:

11:43 - The Guardian relays: "Aftenposten newspaper is reporting police believe it is possible there two more bombs that they haven't located yet."

11:40 - Government minister Hans Kristian Amundsen says to BBC News that "people are believed to still be trapped in the building and the focus is on rescuing people." Prime Minister Jens Stoltenberg was not at the building at the time of the explosion, the news outlet says.

11:31 - A press officer at the Oslo police station tells CNN: "We don't know if this comes from a terrorist action, we don't know yet. We don't know exactly how many explosions were yet," the spokesperson said.

11:16 - BBC correspondent Leif Landsverk reports: "The city centre is now being evacuated. The central train station is now closed."

11:11 am EST - ABC News reports that the explosion was a "result of a massive vehicle bomb, according to U.S. government sources on the scene."

11:04 - In summary of the reports we've seen so far: a large explosion (possibly two) hit government office buildings housing the prime minister in downtown Oslo, Norway. Although the prime minister and his staff appear to be unharmed, at least eight have been confirmed injured and one has been reported dead. The live blogs we're following include those from Reuters, The Guardian, CNN and BBC News. Images and video are below (live video here).

10:57 - "We can confirm that everybody who was working in the prime minister's office today are safe," says Senior adviser Oivind Ostang to Norwegian TV2 (via The Guardian). A BBC correspondent in Oslo, Athar Kaleem, describes the scene: "It was a massive explosion, I was at least 1km away from the scene but I felt the explosive in my feet. Everyone had the same feeling. It seems the explosion got very high shock waves as it broken the mirrors at quite larger distances"

10:54 - The latest Reuters brief confirms a death in the explosion, the reports of those injured vary between eight and "dozens."

10:51 - A spokesperson for the Legevakten Hospital in Oslo tells CNN: "Right now we are not too sure what has happened, we are watching the news and talking to the other hospitals," the spokesperson said. "We don’t know what caused it or how many people are injured."

10:47 -The Associated Press relays this screen image of the smoking surrounding area:

10:44 - The Guardian's live account relays a witness report to the BBC: "A Norwegian reporter told the BBC she is in a building five blocks away and its windows have been blown out by the explosion. She used the word 'bomb' before clarifying that she had no evidence the cause of the explosion was a bomb"

10:42 - Live video can be viewed on Norwegian TV (no English translation) here.

10:39 - The Telegraph relays that dozens are injured, with no casualty reports at present.

10:35 - @Mpoppel, founder of @breaking news, relays the Oslo police statement: "There has been a large explosion at the government headquarters. The police was notified at 1526 this afternoon."

10:33 am EST - CNN relays from Norwegian broadcaster NRK that a second blast has been reported. The report has been disputed however: "NRK: Reports of a second blast are not true; sound was caused by falling debris/glass" (via @Mpoppel)

Original Post:

Multiple outlets are reporting that an explosion has damaged office buildings in downtown Oslo, Norway. The AP, via Breaking News, says that offices are being evacuated. Reuters writes that the explosion blew out the windows of a government building housing the Prime Minister Jens Stoltenberg's office.

The blast blew out most windows on the 17-storey building housing Stoltenberg's office, as well as nearby ministries including the oil ministry, which was on fire.

Eight people were said to have been injured, although the Prime Minister has been reported by the AP to be unharmed. Christian Aglen, at Norway's financial news website (E24.no), tweets the lede picture above: "Unreal. An entire block has exploded!" Several more images have been circulated by Norwegian broadcasters. Video is below: