(CNN) -- Authorities imposed a curfew in the Iraqi city of Ramadi following the arrest of a prominent Sunni lawmaker in a raid that left at least two people dead, police officials said Sunday.
The arrest of Ahmed al-Alwani, one of the main organizers of the anti-government demonstrations in the Sunni-dominated Anbar province, has raised fears of a possible retaliatory strike against Iraqi forces.
The curfew is in place until further notice, the police officials said.
The arrest comes as violence has reached its worst levels since the height of the Iraq War, when sectarian fighting pushed the country to the brink of civil war.
Al-Alwani, a staunch critic of the Shiite-dominated government of Nuri al-Maliki, was wanted on a warrant issued by the government alleging the incitement of sectarian strife, said the police officials, speaking on condition of anonymity.
Al-Alwani has accused the prime minister of marginalizing Iraq's Sunni minority.
Al-Alwani's brother and a woman were killed Saturday when Iraqi security forces clashed with the lawmaker's bodyguards at his Ramadi home, the police officials said. Eleven of al-Alwani's bodyguards were wounded, they said.
Meanwhile, 12 members of Iraq's security forces were killed in four separate attacks in the Sunni-dominated city of Mosul, north of Baghdad, police officials said.
Among those killed were six soldiers who died in a suicide car bombing that targeted a military post, the police officials said.
CNN's Yousuf Basil contributed to this report.