KABUL: A suicide attacker on foot blew himself up near a compound belonging to the Afghan intelligence agency in Kabul on Monday, killing six civilians, officials said.

The attacker struck at a time when workers were arriving at their offices. It comes a week after militants stormed a National Directorate of Security (NDS) training centre in the Afghan capital.

Interior ministry spokesman Najib Danish told AFP six civilians in a car were killed when the attacker detonated himself.

"Six people were martyred and three others were wounded," Danish said.

"They were hit when they were passing the area in their Toyota sedan vehicle. We still do not know the target of the attack but it happened on the main road."

The health ministry confirmed the death toll but put the number of wounded at one.

There was no immediate claim of responsibility for the latest attack in Kabul which in recent months has become one of the deadliest places in the war-torn country for civilians.

An AFP reporter at the blast site said the attack happened outside the main entrance to an NDS compound. Security forces have swarmed the area, closing off the main road leading to the building.

Ambulances were seen leaving the scene, apparently taking casualties to hospitals in the city.

"Our initial information shows a blast took place near an intelligence headquarters in Shash Darak neighbourhood of Kabul," deputy interior ministry spokesman Nasrat Rahimi told AFP.

Last week's attack on the NDS was claimed by the Islamic State, which has expanded its presence in Afghanistan since it first appeared in the region in 2015.