According to the UK Guardian, the U.S. embassy in Kabul, Afghanistan has been attacked by a "small" group of insurgents, who Al Qaeda claims are armed with suicide vests, AK-47s and grenades. The report says the attack was done to test the transition of security over to Afghan forces. So far, there are no casualties at the U.S. embassy, and it looks like the insurgents are being hunted down.
"Afghan national security forces and coalition forces immediately responded to the attack, and are still on the scene. Coalition forces are providing air support. There are no reports of ISAF casualties at this time."
They are live-updating the situation.