Two explosions rocked Kabul at about 4pm on Tuesday afternoon in the PD6 area in Darulaman Road, killing 21 people and wounding 45 others.
Officials said the bombers targeted parliament staff leaving for the day.
He said one explosion came after a suicide bomber detonated explosives at the entrance to the offices and the second explosion was a car bomb.
Officials said the bombers targeted a convoy of vehicles carrying government staff leaving the offices.
Hospital officials confirmed 21 people had been killed and 45 wounded. The wounded had been admitted to various hospitals around the city.
MPs said a female member of parliament from Herat was among those wounded while reports indicate that the NDS head for the zone covering PD6 was among those killed.
Taliban has claimed responsibility for the attack and said the target had been a mini bus carrying government staff.