A Terrorist Attack in Oslo, Norway

News I didn't expect to read this morning:

A huge explosion damaged government buildings in central Oslo on Friday including Prime Minister Jens Stoltenberg's office, injuring several people, a Reuters witness said.

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.

Photos are here, here, and here. Video of the aftermath is here. One possible explanation for the explosion (via J.M. Berger) is here. More to come, I'm sure.

Update: ABC is attributing the blasts to a "massive vehicle bomb." Meanwhile, via Brian Fishman, go here for info on the last notable Norwegian terror plot.

Update #2: There has also been a shooting at a summer camp run by the Labor Party in Utøya. Reports right now say that four people may be dead. Norway's former prime minister was scheduled to speak at the camp today.

Update #3: The police say they've arrested the Utøya shooter; they also report finding undetonated explosives in the area. According to Deputy Oslo Police Chief Sveining Sponheim, the perp is "ethnic Norwegian."

Update #4: Meet the man they arrested.