Update (1:19 p.m. EST): The Guardian has word from Tehran police chief Hossein Sajedinia that both British embassy sites in Tehran have been emptied, confirming the initial reports that the protest action is over. According to Reuters, British Foreign Secretary William Hague has confirmed that all embassy staff and their dependents are accounted for. Looks like this thing is effectively over. But the diplomatic fallout has just started as the UK has reportedly summoned Iran's top diplomat in London, protesting the incursion in the "strongest terms," according to Reuters.

 

Update (12:45 p.m. EST): The protesters have left the second UK embassy compound at Qolhak garden, the Reuters live blog reports, citing the Iranian ISNA news agency.

Update (12:41 p.m. EST): The occupation of the main British embassy compound seems to have ended as students leave the building, Reuters reports in its live blog, attributing the news to the semi-official Iranian Fars news agency. It's an early report, of course, so stay tuned for confirmation.

Update (12:25 p.m. EST): The U.S. White House has joined an international chorus condemning the attack on the embassy. Reuters has quotes from the statement from White House spokesman Jay Carney, who follows leaders in Russia, France, and, of course, Britain:

"Iran has a responsibility to protect the diplomatic missions present in its country and the personnel stationed at them," White House press secretary Jay Carney said in a statement.

"We urge Iran to fully respect its international obligations, to condemn the incident, to prosecute the offenders, and to ensure that no further such incidents take place either at the British Embassy or any other mission in Iran. Our State Department is in close contact with the British government and we stand ready to support our allies at this difficult time," Carney said.

The White House statement comes shortly after Iran's own foreign ministry said it "regrets the protests that led to some unacceptable behaviors." 

Update (12:10 EST): This is kind of odd: As protesters looted the British embassy, one thing they took was a large poster of a scene from Pulp Fiction. We'll post a photo when it becomes available. Here's the photo, via Reuters:

Update (11:49 a.m. EST): The Guardian made a Google map showing the relative locations of the main British embassy (to the south) and the diplomatic compound at the Qolhak garden (to the north). The garden, which houses British diplomats and their families, has spurred controversy between Britain and Iran in the past, with Tehran characterizing the British as "occupiers" of the space.

Update (11:19 a.m. EST): There was some confusion about hostages that may have been taken, but now it appears six workers did get caught inside a demonstration at the Qolhak garden in northern Tehran (a property of the British embassy), and police have secured their release. The semi-official Fars news agency reported that police rescued the six workers after demonstrators stormed the garden and surrounded them. The report follows some conflicting news earlier. The New York Times reports: "Iran’s semi-official Mehr news agency said six people from the embassy were seized by Iranian students from Tehran universities but inexplicably withdrew the report minutes later. (Note: As The Guardian points out, the British embassy hasn't commented on the status of its people, so the Fars report should be treated with caution.)

Update (10:21 a.m. EST): The situation is still chaotic, The Telegraph reports, but the official IRNA news agency says security forces have reportedly sealed off the entrance to the embassy. It's still unclear how many people are inside:

"Security forces have been able to close the gate now and they are not allowing people to go inside," IRNA said. The student news agency ISNA said there were 200 people outside the compound in the Qolhak garden of north Tehran.

Students in Tehran stormed the British embassy there on Tuesday, forcing their way inside, where they threw papers from the windows and took down the British flag. The attack started with dozens protesting outside the building "to commemorate the death anniversary of Iranian nuclear scientist Majid Shahriari who, according to Iranian authorities, was murdered by Israeli’s Mossad in cooperation with UK’s MI6," Al Arabiya reportsThe Times also reminds us that Iran had moved on Monday to downgrade diplomatic relations with Britain in retaliation for Western sanctions. The Al Arabiya report suggests the British embassy was a focal point for generalized rage against the West. "The protesters chanted 'Down with Britain,' 'Down with America,' 'Down with Israel,' and 'Students are Awake and Hate Britain,' according to Fasrs." In its live blog of the situation, The Telegraph's latest report is that "a second British embassy compound elsewhere in Tehran has been stormed and "classified" documents have been seized, the IRNA news agency reported." Meanwhile, black smoke has been reported coming from the main British embassy building, according to The Telegraph.