Iraqi forces have killed 10 gunmen in clashes that erupted as they cleared a year-old Sunni Arab protest camp.
Gunmen later replaced security forces on some streets of Ramadi city, the capital of Anbar province, near the protest site west of Baghdad.
Forty-four Iraqi MPs announced their resignation after the violence on Monday. They also demanded "the withdrawal of the army... and the release of MP Ahmed al-Alwani", a Sunni who backs the protesters and who was arrested during a raid on his home in Ramadi on Saturday.
An AFP journalist in Ramadi reported heavy fighting, and saw helicopters firing into the area of the protest site.
A doctor at Ramadi hospital said 10 gunmen were killed and 30 wounded.
The fighting spread to the nearby city of Fallujah, where police Captain Omar Oda said militants burnt military vehicles.
Prime Minister Nuri al-Maliki's spokesman, Ali Mussawi, said tents at the protest site had been removed and the road towards neighbouring Jordan and Syria reopened.
This had been done "without any losses, after Al-Qaeda and its members escaped from the camp to the city, and they are being pursued now", Mussawi told AFP.
He was echoing a claim made on December 22 by Maliki, who said "the sit-in site in Anbar has turned into a headquarters for the leadership of Al-Qaeda".
Protests broke out in Sunni Arab-majority areas of Iraq late in 2012 after the arrest of guards of then-finance minister Rafa al-Essawi, a Sunni Arab, on terrorism charges.
Sunnis saw this as another example of the Shi'ite-led government targeting their leaders.
In December 2011, guards of vice president Tareq al-Hashemi, another prominent Sunni politician, were arrested and accused of terrorism. Hashemi fled abroad and has since been sentenced to death for charges including murder.
Sunni Arabs say they are marginalised by the government and picked on by security forces.
The government has made some concessions, such as freeing prisoners and raising the salaries of anti-Qaeda militiamen, but underlying issues remain unaddressed.
The violence continued elsewhere on Monday, with at least 17 people, among them eight security forces members, killed in attacks.
More than 6,750 people have been killed in violence in the past year, according to AFP figures based on security and medical sources.
