A suicide bomber who was wounded in an exchange of gunfire with a police patrol in western Iraq on Wednesday blew himself up in a hospital where he had been taken for treatment, wounding two people, police said.
In the earlier clash in the town of Hit, 130 km (80 miles) west of Baghdad, two other suicide bombers killed three police officers, the police said.
Anbar province, where the attacks took place, was the heartland of a fierce Sunni Islamist insurgency after the 2003 U.S.-led invasion and in the grip of Al-Qaeda.
But local Sunni tribal chiefs turned on Al-Qaeda in 2006 and 2007, helping U.S. forces bring relative peace to Anbar, a sprawling desert province bordered by Saudi Arabia, Syria and Jordan.
Tensions have simmered in Iraq since an inconclusive election in March, which produced no outright winner and has yet to yield a government.
A Sunni-backed alliance won a slim victory in the vote but a union of the main Shi'ite-led factions is expected to take the lead in the tussle to form a coalition government.
Insurgent groups have sought to exploit the political vacuum since the election to stoke sectarian tensions.
Al-Qaeda's Iraqi affiliate claimed responsibility for brazen suicide assaults on the Iraqi central bank and the Trade Bank of Iraq this month, and police in Anbar and elsewhere have come under constant attack.