At least four people were killed Monday when a bomb tore through a bus in Kabul, an official said, marking the second day straight that attackers have targeted a bus.
The vehicle was taking workers home from a government watchdog agency ahead of the Eid holidays marking the end of Ramadan when the bomb exploded.
Farid Ahmad, a spokesman for the Independent Administrative Reform and Civil Service Commission (IARCSC), told AFP the bomb had been concealed on a bicycle along the side of the road.
"Unfortunately, we have lost four colleagues, nine have been wounded", Ahmad said.
Interior ministry spokesman Nasrat Rahimi put the toll at five dead and 10 wounded -- all of them civilians.
He said the explosion had been caused by a sticky bomb, a common threat in Kabul where criminals and insurgents slap explosives under vehicles.
ISIS group's Afghanistan affiliate later claimed responsibility for the attack.