At least 28 people have been killed and more than 320 others injured in a brazen attack by Taliban militants in central Kabul.
Police chief Abdul Rahman Rahimi said on Tuesday civilians and members of the Afghan security forces were among the dead and wounded.
"Many of those wounded are in serious condition," Health Ministry spokesman Mohammad Ismail Kawoosi said.
The attack, claimed by the Taliban, targeted the offices of Afghanistan's main security agency during the Tuesday morning rush hour.
In a statement, the Presidential Palace condemned the attack "in the strongest possible terms," saying a number of people had been killed or wounded.
A thick plume of black smoke was seen rising from the vicinity of the sprawling US embassy in the Afghan capital after the powerful blast.
Warning sirens were sounded at the embassy compound, which is also close to NATO headquarters in Afghanistan.
An Afghan official said a possible bomber carried out the attack which was followed by gunfire as the area was surrounded by security forces.
Taliban militants have stepped up their attacks against foreign troops and Afghan security forces since announcing the start of their spring offensive last week.
In a separate development, a US drone attack in eastern Afghanistan has killed several people.
According to local Afghan officials in Nangarhar Province, a US drone strike targeted and killed at least five militants affiliated with the Takfiri Daesh terrorist group.
The raid was conducted in the Achin district of Nangrahar.
Afghanistan, parts of which are largely known as being Taliban’s turf, has seen a rise in the number of Daesh militants in the recent past. Nangarhar, in particular, has become a focal point of Daesh convergence.
The US military estimates that between 1,000 and 3,000 Daesh fighters are operating across Afghanistan.