The Iraqi army has begun moving tanks and security personnel into the western al-Anbar governorate, after Iraqi security forces arrested Ahmed al-Alwani, a prominent Iraqi MP, during a raid on his home in Ramadi, security officials said.
At least five people, including Alwani’s brother and guards, were killed in the clashes sparked by the raid on Saturday, while 18 people, including 10 security forces members, were injured, according to two police officers and a doctor from the Ramadi hospital.
The Iraqi defence ministry said Alwani's brother, Ali, who was wanted on terrorism charges, was the target of the raid.
"Army troops with police special forces were trying to arrest Alwani from his house, but fierce fighting erupted. Five bodies, including one woman, were taken to Fallujah hospital," one police source told the Associated Press news agency.
It was not immediately clear why Alwani was arrested, though he is a well-known supporter of Sunni Arab anti-government protesters camped on a highway near Ramadi.
Alwani is from the Iraqiya Bloc and has been accused of making derogatory remarks about the Shia community in Iraq. He is a regular speaker at rallies against Nouri al-Maliki's government.
The raid threatens to inflame widespread discontent among Iraq's Sunni Arab minority and could compound rampant violence plaguing the country.
AFP news agency reported that hundreds of people armed with automatic weapons protested at Alwani's home in Ramadi after the raid. "With soul, with blood, we sacrifice for you, doctor," they shouted, referring to the MP.
Parliament speaker Osama al-Nujaifi, a Sunni, sharply criticised the arrest and described it as "treading on the core of the Iraqi constitution and a clear violation of its articles".
Speaking to Al Jazeera from Baghdad, political analyst Ahmed Rushdi said the Alwani family, an influential tribe in al-Anbar governorate, has issued an ultimatum to Iraq's government, threatening to attack army camps in al-Anbar unless Alwani is released.
"Politically, it is a very harsh issue for the Sunni leaders because they are entering the elections with so many lists, and they are governing the "Sunni triangle" and they will attack the Shia dominancy in the Iraqi government. There will be a political [crisis] between the Sunni and Shia, which means it will be a sectarian issue," Rushdi said.