KABUL, Dec. 11 (Xinhua) -- At least four security forces members and an assailant were killed and six others wounded after a suicide car bomb blast struck an Afghan security forces' convoy in western Kabul on Tuesday, an Interior Ministry official said.

"The incident occurred roughly at 9:20 a.m. local time in Bala Chinar area of Paghman district. The given information was based on the initial findings of our police. So far, we have no more details, but we will try to get more information," the official who declined to be named told Xinhua.

The blast caused a plume of gray smoke to rise above the scene, witness Mohammad Maruf told Xinhua, adding that the convoy was carrying personnel of National Directorate of Security, country's primary intelligence agency.

Further details about the incident are still forthcoming amid the absence of any official statement.

No group has claimed responsibility for the attack yet.

The capital city with a population of nearly 5 million has been hit by series of terror attacks over the past couple of years.