Interior Ministry spokesman Sediq Sediqqi says at least two policemen were also wounded in the attack, which came as Afghans mark Independence Day from Britain in 1919.
Sediqqi says one suicide bomber first detonated a car laden with explosives outside the British Council in the western part of Kabul on Friday morning.
A second bomber penetrated inside the complex and set off an explosives vest. The blasts set off a five-hour-long gunbattle between Afghan security forces and an unknown number of insurgents inside the compound.
