BAGHDAD (AFP) - The Iraqi government has lost control of the city of Fallujah, which is now held by Al-Qaeda-linked militants, a senior security official in Anbar province said on Saturday.

"Fallujah is under the control of ISIL," the official said, referring to the Islamic State of Iraq and the Levant.

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 were insurgent strongholds.

Fighting erupted in the Ramadi area on 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.

It then spread to Fallujah, and security forces later withdrew from areas of both cities, leaving them open for ISIL to move in.

Fighting between police and allied tribesmen on one side and ISIL militants on the other killed more than 100 people in Ramadi and Fallujah on Friday, security officials said.

It was the deadliest single day for Iraq in years.