Nearly 200 people were injured on Tuesday in a suicide bombing near the Afghan presidential palace in capital Kabul, an official said.
"Several dead bodies and 198 injured have been taken to hospitals," health ministry spokesman Aziz Qawosi said.
It is difficult to say the exact number of casualties at the moment, Xinhua news agency quoted the official as saying.
Earlier reports said 20 people were killed in the blast. However, there was no confirmation of the casualties.
The deadly explosion apparently targeted a Secret Service Unit tasked with protecting VIPs, TOLO News reported.
Security forces cordoned off the area as heavy gunfire continued after the explosion. Reports said gunmen managed to enter the unit's perimeter.
Afghan President Ashraf Ghani condemned the incident and labelled it a terrorist attack.
The Taliban militant group has claimed responsibility for the attack.