MANAMA, Bahrain (AP) — A bomb blast in Bahrain killed three policemen as they were dispersing “rioters and vandals” on the outskirts of the capital Manama, authorities said Monday in an escalation likely to increase tensions between security forces and hard-line protesters.

The Interior Ministry said in a statement that the police were killed Monday while confronting violent protesters, and that initial indications suggest the blast was planted near a lamp post and was detonated remotely. Two other explosions occurred nearby and another bomb was defused, the ministry said.