Kabul: In two separate roadside bombs went off in a western Afghanistan province on Tuesday, killing eight civilians and four policemen.

One woman, a child and six men were killed when the blast hit a bus in Del Aram district of Farah province, deputy provincial governor Mohammad Younus Rasuli said.

Similar attacks and ambushes on Afghan and foreign troops by Taliban insurgents have occurred on this road in recent months.

In the second incident, four policemen were killed and three others wounded  when their vehicle was hit by a bomb in Logar province south of Kabul.

In another incident on Tuesday, US-led troops killed several Taliban militants in an operation in Helmand province in the south, the US military said in a statement.