AGENCIES: At least 12 people were killed and several others sustained injuries in a blast from a bomb planted on a bus near the Iraqi city of Karbala, south of Baghdad, police officers said.

 An explosive device planted on the bus was detonated at a northern entrance to the city, setting fire to the vehicle, said police spokesmen from the blast site.

Quoting local officials, the Associated Press said five passengers were wounded in the explosion, which occured as the bus was passing through an Iraqi army checkpoint between Karbala and the town of al-Hilla.

One official told The Associated Press that before the blast, a passenger exited the minibus but left a bag containing explosives under one of the seats. The device was then detonated remotely at the checkpoint.

No one has claimed responsibility for the attack yet.

All of the dead were civilians killed in the explosion and subsequent fire in the bus, officials said.

The bombing took place during a holy period marked by Shias between two important religious events, Ashoura and Arbaeen.