Al-Qaeda-linked militants on Friday advanced into new areas of one major Iraqi city, as part of another remained outside the control of security forces, police said.
Districts 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.
Fighters from the Al-Qaeda-linked Islamic State of Iraq and the Levant (ISIL) advanced in early morning clashes into areas in 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 after late 2006, to wrest control of Anbar province from militants.
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 country's main anti-government protest camp.
The site was one of several that sprang up after Sunni Arabs began protesting in late 2012, condemning what they called the marginalisation of their minority community and its unfair targeting in heavy-handed security forces tactics.
The violence in Ramadi 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 that was demolished on Monday, 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 province.
And while the camp's closure has removed a physical sign of Sunni Arab grievances, the perceived injustices that underpinned the demonstration remain unaddressed.