Al-Qaeda-linked militants advanced Friday into new areas of one major Iraqi city and held part of another, after days of violence sparked by the removal of an anti-government protest camp.
Parts of Ramadi and Fallujah, west of Baghdad, have been held by militants for days, harkening back to the years after the 2003 US-led invasion when both cities in Anbar province were insurgent strongholds.
Fighting began in the Ramadi area Monday, when security forces removed the main anti-government protest camp set up after demonstrations broke out in late 2012 against what Sunni Arabs say is the marginalisation and targeting of their community.
Anger in the Sunni Arab minority remains high, helping to fuel the worst violence to hit Iraq in five years.
Fighters from the Al-Qaeda-linked Islamic State of Iraq and the Levant (ISIL), which operates in both Iraq and neighbouring Syria, advanced amid early morning clashes into areas of central Ramadi and deployed snipers on one street, a police captain said.
A police colonel said the army had re-entered areas of Fallujah, between Ramadi and Baghdad, but that a around a quarter of it remained under ISIL control.
Soldiers and armed tribesmen held the rest and had also surrounded the city, he said.
However, another senior officer, a police lieutenant colonel, said that while soldiers had deployed around the city, they had yet to enter Fallujah.
The city was the target of two major assaults after the 2003 invasion, in which American forces saw some of their heaviest fighting since the Vietnam War.
American troops fought for years, aided by Sunni tribesmen from late 2006, to wrest control of Anbar from militants, suffering almost one-third of their total fatalities during the war in the province, according to independent website icasualties.org.
But two years after US forces completed their withdrawal from Iraq, the power of militants in the province is again on the rise.
Clashes erupted in the Ramadi area on Monday as security forces tore down the sprawling anti-government protest camp on a nearby highway.
The violence then spread to Fallujah, and a subsequent withdrawal of security forces from areas of both cities cleared the way for ISIL to move in.
Police and tribal fighters battled ISIL in east Ramadi on Thursday, but the fighting eased after several hours with militants still controlling some areas.
Iraqi special forces also clashed with militants in Fallujah on Thursday, their commander said.
At least 14 people were killed on Monday and Tuesday in Ramadi, but casualties from the later clashes there and in Fallujah were not immediately clear.
Prime Minister Nuri al-Maliki had long sought the closure of the protest camp near Ramadi, dubbing it a "headquarters for the leadership of Al-Qaeda".
But the removal of the camp has come at the cost of a sharp decline in the security situation in Anbar.
And while the camp's closure has removed a physical sign of Sunni Arab grievances, the perceived injustices that underpinned the demonstration remain unaddressed.
Violence in Iraq last year reached a level not seen since 2008, when the country was just emerging from a brutal period of sectarian killings.
Sunni anger helped fuel the surge in unrest, boosting recruitment for militant groups and decreasing cooperation with security forces, while the civil war in Syria also played a role, experts say.