Four Afghan civilians were killed as a roadside bomb struck their car in Kandahar province, 450 km south of Afghan capital Kabul, on Saturday, the Kandahar provincial administration said Sunday.

"The tragic incident occurred in Shorabak district yesterday, as a result four civilians were killed," according to a press release of the provincial administration.

Police also discovered two more explosive devices planted on the road and defused them, the press release said.

It blamed the attack on the enemies of peace, a term used by Afghan officials against Taliban militants. However, the outfit has yet to make any comment.