* Fighting continues in Anbar for third day
* Shi'ite PM Maliki reinforce army in Anbar
* Sunni militants seizing police, local govt buildings
Islamist militants stormed police stations in several cities of Iraq's western province of Anbar on Wednesday, seizing weapon caches and freeing prisoners after security forces dismantled a Sunni Muslim protest camp on Monday.
The attacks on three police stations in Falluja, Ramadi and Tarmiya represent a serious escalation in the confrontation between Iraqi Sunni groups and the Shi'ite-led government of Prime Minister Nuri al-Maliki.
Sunni anger at the government's crushing of a protest movement has inflamed Iraq's already deeply rooted sectarian tensions. The camp dismantled on Monday has been seen as an irritant to Maliki since it was set up to protest against perceived Sunni marginalisation a year ago.
"Gunmen in large numbers surrounded the three police stations in Falluja and forced all policemen to leave without their weapons if they wanted to spare their lives. All of us left, we didn't want to die for nothing," a policeman stationed at one of the three stations told Reuters.
The gunmen then took control of a local government building nearby, deploying snipers on its roof to prevent the security forces from retaking command of the police stations in Falluja, 50 kilometres west of Baghdad.
Clashes between gunmen and security officials in Ramadi, another city in Anbar, continued for a third day on Wednesday, and also involved assaults on police stations by militants driving vehicles mounted with machine guns.
In a separate attack, at least four policemen were killed and 12 more wounded when gunmen attacked a police headquarters in the mainly Sunni town of Tarmiya, north of Baghdad, police reported.
Dozens of trucks loaded with gunmen were roaming the streets in Falluja and Anbar, and three police vehicles were set ablaze near one police station in Ramadi, a police source said.
The prime minister has offered some concessions to Sunni protesters, including proposed reforms to tough anti-terrorism laws, but most Sunni leaders say they will not be enough to appease the demonstrators.
The Shi'ite premier may also seek to consolidate his position before 2014 parliamentary elections by taking a tough stance against hardline Sunni Islamists.
More than 8,000 people have been killed in such violence this year.
Wednesday's attacks began only hours after a decision by Anbar's governor to lift a curfew imposed on Monday after fighting had erupted in various parts of the province.
Maliki had said the civilian police force could resume control over Anbar's security, but that decision was changed after an appeal by the province's governor.
"The governor of Anbar Ahmed Khalaf appealed to the Prime Minister to keep the army in Anbar because al Qaeda fighters managed to enter on Wednesday and controlled some parts of the province," the governor's office told Reuters.
Violence in Iraq has hit its highest levels since the sectarian fighting of 2006-7, which killed tens of thousands of people.