BOMBS have exploded at four Sunni mosques in the Baghdad area after prayers, killing four people and raising the death toll from a four-day wave of violence in Iraq to 195.

Iraqi security forces also began moving back into the northern town of Sulaiman Bek after gunmen who seized it withdrew on Friday.

The bombings at three Sunni mosques in Baghdad and a fourth north of the capital, which killed at least four people and wounded 50, came after more than a dozen people were killed in attacks on Sunni mosques on Tuesday.

Gunmen, meanwhile, pulled out of Sulaiman Bek under a deal worked out by tribal leaders and government officials, local official Shalal Abdul Baban and municipal council deputy chief Ahmed Aziz said.

The gunmen had swarmed into the predominantly Sunni Turkmen town on Wednesday after deadly clashes with the security forces, who pulled back as residents fled.

Baban also said that helicopter fire wounded six people on the roof of a house in the town early on Friday.

Army Staff General Ali Ghaidan Majeed told AFP on Thursday that the gunmen in Sulaiman Bek, who he said number about 175, had been given 48 hours to withdraw or face attack.

The gunmen's seizure of the town came amid a surge of violence which began on Tuesday when security forces moved in against anti-government protesters near the Sunni Arab northern town of Hawijah.

The operation sparked clashes that left 53 people dead.

Dozens more were killed in subsequent unrest, much but not all of it linked to Tuesday's clashes, bringing the death toll to 195 by Friday.

The violence is the deadliest so far linked to demonstrations that broke out in Sunni areas of the Shi'ite-majority country more than four months ago.

The protesters have called for the resignation of Prime Minister Nuri al-Maliki, a Shi'ite, and railed against authorities for allegedly targeting their community.

Seven gunmen died carrying out three separate attacks on security forces south of the northern city of Kirkuk on Friday, a high-ranking army officer and a medical source said.

Gunmen also killed a soldier and wounded two police in an attack on a checkpoint in Al-Sharqat, north of the capital, late on Thursday, a police colonel and a doctor said.

And three hours of fighting in Fallujah, west of Baghdad, killed three federal police and wounded six late on Thursday, police Lieutenant Colonel Yassir Hamid al-Jumaili and a doctor said.

The clashes saw gunmen take control of three checkpoints on the outskirts of the overwhelmingly Sunni Arab city after they were abandoned by federal police, Jumaili said.

He said they then turned the checkpoints over to local police, who returned them to federal police on Friday.