Residents are fleeing the Iraqi city of Fallujah, amid artillery fire and air strikes by government forces on Sunday.
A shop window in Ramadi. Photo: AFP
The BBC reports the government admitted it had lost control of the city - west of Baghdad - to fighters linked to al-Qaeda and allied tribesmen.
Fighting is also reported in Ramadi, also in Anbar province.
Correspondents say Fallujah is a highly symbolic city for many Iraqis, particularly Sunni Arabs. It is remembered for the battles fought there between insurgents and US forces in 2004.
Fighters from the Islamic State in Iraq and the Levant, known as ISIS, are reported to control the south of Fallujah. Tribesmen allied with al-Qaeda hold the rest of the city.
US Secretary of State John Kerry said on Sunday the Obama administration will help Iraq in the fight, but it's not planning to send troops back to Iraq.
Mr Kerry said he is confident the Iraqi government can defeat them.
