At least seven policemen were killed and 15 wounded in a series of attacks targeting police forces in Iraq's western province of Anbar, a provincial police source said on Thursday.

In one attack, two suicide bombers blew up their explosive vests at a police checkpoint at the entrance of a police station in the center part of the provincial capital of Ramadi, some 110 km west of the Iraqi capital of Baghdad, the source told Xinhua on condition of anonymity.

Afterwards, a third suicide bomber drove his explosive-laden car into the same police station and blew it up, the source said, adding at least three policemen were killed and seven others wounded by the blasts, which destroyed part of the building.

In a separate incident, a suicide bomber rammed his explosive- laden car into a police checkpoint in al-Jazira area in northern Ramadi, killing three policemen and wounding six others, the source said.

Late on Wednesday night, a suicide bomber blew up a car packed with explosives into a police convoy on the highway near the city of Rutba, some 375 km west of Baghdad, killing a police officer and wounding two policemen, the source added.

Insurgent attacks are still common in the volatile Sunni Arab area in western Baghdad that stretches through Anbar province to Iraq's western border with Syria, Jordan and Saudi Arabia.