Bombing kills at least 21 in Sri Lanka

COLOMBO, Sri Lanka (CNN) - At least 21 commuters were killed and more than 53 wounded when an explosion hit a crowded bus in a town south of the capital of Sri Lanka on Friday, police said.

Police accused Tamil Tiger rebels of carrying out the attack in Moratuwa, a southern suburb of Colombo. Police said they also discovered and diffused a claymore mine in the same place, preventing another explosion.

Police and soldiers sealed off an area around the scene and searched for suspects. Authorities also intensified security in Colombo.