A suicide car bomber attacked a police convoy in Baghdad today.
A policeman and a bystander were killed and at least five people wounded, police said.
Iraqi and US troops raided a major Sunni mosque in the capital after Friday prayers, killing or seizing several people, according to local witnesses.
Two people were killed and 14 wounded, hospital sources said after national guards backed by US troops tried to storm the Hanifa mosque. Witnesses said worshippers threw shoes at the troops, a grave insult in Islam, and soldiers opened fire.
The raid followed more than 100 arrests in a Sunni area of Baghdad the day before, when police said they detained some militants suspected of escaping Fallujah.
Iraq's interim government has underlined its intention of crushing revolt among the once dominant Sunni Arab minority to prevent it derailing plans for an election in January.
In the troubled northern city of Mosul, a fire destroyed voter-registration papers and other materials being stored at a warehouse in anticipation of the vote.
A car bomb in the city wounded a US soldier. Also in the north, another Iraqi policeman was killed in a mortar attack on a police station at Muqdidiya.
Police commandos and US soldiers detained three people at a Mosul hospital they said had been used to treat rebels wounded in recent fighting, when insurgents put most of the city's new police force to flight.