Updates

2:25 pm - Reports are now confirming that a 60-year-old woman died in the explosion. Thirty-nine people were injured, according to Magen David Adom.

11:45 - In Gaza, Islamic Jihad denied involvement in the explosion, but a spokesman said the group "applauds all efforts to respond to the crimes committed daily against our people," according to the AP.

11:37 - Israeli radio is reporting that one woman has died of wounds from the explosion. Israeli authorities are blaming Palestinian militants for the blast, the Associated Press explains, but so far no group has claimed responsibility.

10:27 - Foreign Policy's Blake Hounshell speculates on the meaning of the recent escalation of tensions between Israel, Hamas, and other Gaza factions: "Is this the start of the third intifada we've been hearing so many warnings about? Or an isolated attack intended to change the subject?"

10:23 - The Associated Press says the explosion represents the "first militant attack" in Jerusalem in several years: "Jerusalem suffered dozens of suicide bombings that targeted buses and restaurants during the second Palestinian uprising last decade. But the attacks have halted in recent years. Jerusalem last experienced a suicide bombing in 2004."

10:15 - Haaretz is reporting that the blast was caused by an explosive device hidden in a bag near a telephone pole, not by a suicide bomber. It says four people are seriously injured. 

Original Post (9:39 am EST)

Israel's Haaretz newspaper is reporting that a bomb exploded on Wednesday near two public buses in Jerusalem outside the International Convention Center, near the city's central station. At least 25 people are reported to be wounded, with Magen David Adom emergency services reporting no fatalities. Ambulances are taking the injured to the Hadassah Hospital in Ein Karem. It's not yet clear whether a suicide bomber was behind the attack, Haaretz says.

On Tuesday night and Wednesday morning, Palestinian rockets struck the Israeli cities of Beersheba and Ashdod, with Islamic Jihad--a Gaza-based group and occasional Hamas ally--claiming responsibility and Israel launching retaliatory air strikes, according to The Guardian. A round of shelling between Israel and Hamas on Tuesday in Gaza killed four Palestinian civilians and five militants. The Guardian calls the attacks on Beersheba and Ashdod "the biggest escalation of hostilities since Israel launched its assault on Gaza two years ago." Silvan Shalom, a deputy to Prime Minister Benjamin Netanyahu, said on Israeli radio that Israel might have to return to its 2008-2009 operation in Hamas-controlled Gaza.