MOSUL – Nearly 50 people were killed in clashes on Thursday here, sources said, on the third day of the most widespread violence in Iraq since U.S. troops withdrew in December 2011.

More than 100 people have been killed in fighting since Tuesday, when troops stormed a Sunni protest camp, triggering clashes that quickly spread to other Sunni areas in western and northern provinces.

Thousands of Sunni Muslims have taken to the streets since December in protest at the perceived marginalization of their sect since the U.S.-led invasion overthrew Saddam Hussein and empowered majority Shi’a through the ballot box.

Shi’a Prime Minister Nuri al-Maliki’s coalition took the lead in eight of the 12 provinces that held provincial elections at the weekend, including the capital Baghdad, preliminary results showed on Thursday.

The strong showing by Maliki’s State of Law alliance – based on 87 percent of the results – consolidates his position ahead of parliamentary elections due in 2014, when he has hinted it will be time to form a majority government.

Iraqi politics are deeply split along sectarian lines, with Maliki’s government deadlocked over how to share power among Shi’a, Sunni Muslims and ethnic Kurds, who run their own autonomous region in the north.

The delicate ethno-sectarian balance has come under growing strain from the civil war in neighboring Syria. 

Violence, including bomb attacks that have killed dozens of people at a time, has increased across Iraq this year; about 1,365 people have been killed so far in 2013.

Gunmen attacked Mosul, 240 miles north of Baghdad, on Wednesday night and took control of western parts of the city. Military sources said federal police and the army regained control after surrounding a police headquarters occupied by militants, who were holding 17 hostages. The federal police chief said 31 militants had been killed in the fighting.

A source at a local morgue said it had received the bodies of nine militants and 15 policemen but others had yet to be recovered.

Insurgents also seized the town of Sulaiman Pek, 100 miles north of Baghdad, overnight on Wednesday. Troops and tanks surrounded the town and gave militants 48 hours to lay down their arms and leave, threatening to attack.

In a televised speech, Maliki warned Iraq was in great danger, calling on clerics and tribal leaders to rein in those responsible.  

-Reuters