KABUL, Afghanistan — A roadside bomb hit a bus today in western Afghanistan, killing eight civilians, while another roadside bomb south of the capital left four Afghan police dead, officials said.

The bomb hit the bus in Farah province as it was traveling to neighboring Nimroz province, said Farah deputy governor Younus Rasuli.

Eight civilians were killed and another was wounded, Rasuli said. All casualties were men.

The western Afghan provinces bordering Iran are frequently hit by insurgent attacks. Militant bomb attacks usually target military convoys, but civilians are often killed.

In Logar province, south of Kabul, four police were killed by a roadside bomb today, said deputy police chief Abdul Majid Latifi.

Also in Logar, protesters blocked a road after foreign troops killed a cleric during an operation before dawn today, local leaders said.

Abdul Hakim Sulaimankhel, chief of Logar's provincial council, said foreign troops raided a house and killed a cleric in Pul-e Alam district. Four suspects were arrested.

He said 300 protesters carried the cleric's body to a main road and blocked it.

The U.S.-led coalition said it was not involved in the operation, and NATO officials did not immediately have details of the incident.

In southern Helmand province, U.S.-led coalition troops killed "several militants" today during an operation targeting weapons smugglers in Garmser district. The forces also discovered and destroyed a cache of narcotics.

U.S. Marines moved into Garmser late last month and have been battling militants in almost daily battles ever since.

More than 1,200 people — mostly militants — have died in insurgency-related violence so far this year, according to a count by The Associated Press.