Journalists on the scene report intermittent gunfire and say the attack appears to be ongoing.
There is no word on casualties in the latest attack, which followed a suicide car bombing earlier in the day. That attack killed at least five people in a vehicle from the British embassy. One of the dead was a British national.
"I strongly condemn this despicable attack by the Taliban against those who were serving to help improve conditions in Afghanistan," said General John Campbell, commander of the International Security Assistance Force (ISAF). "Those who commit such murderous acts have no place in the future of this country."
Attack condemned
In Rome, visiting British Foreign Secretary Philip Hammond condemned the attack. Hammond said the victims had been both British and Afghan.
Afghan officials said the first attack Thursday wounded 33 other people, all of them Afghans.
The Taliban claimed responsibility for the car bombing, saying it "targeted foreign invading forces."
Afghanistan's capital has been hit by a wave of attacks recently. Most foreign combat forces that have been supporting the Afghan government are preparing to leave the war-torn country next month.
Earlier this week, a bomb blast in Kabul killed two American soldiers.
