Four policemen were killed and 31 others wounded in overnight clashes between gunmen and Iraqi security forces in central Baghdad, an Interior Ministry source said on Tuesday.

Fierce clashes broke out at about 6:00 p.m. (1400 GMT) between unidentified gunmen and Iraqi police and army forces in the volatile Haifa Street, the source told Xinhua on condition of anonymity.

The casualties among the gunmen were not clear as the Iraqi security forces withdrew from the predominantly Sunni neighborhood after four hours of fighting, the source said.

Haifa Street is a thoroughfare running through central Baghdad, which has seen heavy violence between security forces and insurgents in recent weeks.

Separately, two roadside bombs went off Tuesday morning near Rubaie Street in Zaiyouna neighborhood in eastern Baghdad, one of them hit a police patrol, wounding two civilians and a policeman, the source said.

Insurgents frequently attack Iraq's fledgling security forces accusing them of collaborating with U.S. occupation.

Source: Xinhua