A suicide bomber wearing an explosives belt blew himself up inside a funeral tent in a Shiite enclave in a volatile province north of Baghdad today, killing at least 20 people and wounding 30, officials said.

Iraqi police and soldiers fanned out today to enforce an extraordinary daytime curfew in Baghdad and three provinces in a bid to halt the wave of sectarian violence that has killed about 120 people since the bombing of one of Shiite Islam’s holiest shrines.