BAGHDAD - More than 50 people were killed and over 100 others wounded in violent clashes and attacks across Iraq on Tuesday, police sources and witnesses said.

Clashes between Iraqi security forces and anti-government Sunni protesters in the northern city of Hawijah on Tuesday morning left at least 25 dead and 153 injured, a local police source told Xinhua on condition of anonymity.

A man is brought to a hospital on a stretcher after after being wounded in a clash between Iraqi forces and Sunni Muslim protesters in Kirkuk, 250 km (155 miles) north of Baghdad April 23, 2013. [Photo/Agencies]

The clashes erupted when hundreds of security members backed by helicopters stormed early Tuesday a sit-in by Sunni Arabs in Hawijah, some 220 km north of the Iraqi capital of Baghdad.

In a bid to ease the tension, Prime Minister Nuri al-Maliki's office said in a statement that Maliki formed a fact-finding committee to probe the incident.

Since last December, the Shiite-led government in Baghdad has been at odds with the Sunni community in north and west of Baghdad, who complained about injustice and marginalization and claimed that the Shiite-dominated security forces indiscriminately arrested their sons and tortured them.

Tuesday's operation on the sit-in sparked the tension between the Sunni tribes and the Iraqi security forces.

Unidentified gunmen attacked an army checkpoint near the site of a sit-in in the city of Ramadi, 100 km west of Baghdad, killing six soldiers and abducted another, a police source said.

Six members of the Iraqi security forces and two protesters were also killed in clashes in the Sulaiman Bek area, 90 km east of the city of Tikrit, 170 km north of Baghdad, the source added.

A Sunni mosque in eastern Iraq was hit by bomb attacks on Tuesday evening, leaving at least six killed and eight others wounded, security officials said.

Three roadside bombs exploded near the mosque in Muqdadiyah area near Baquba, 60 km northeast of Baghdad, local police sources told Xinhua.

Earlier, two bombs went off near a mosque in southern Baghdad, killing seven people, the sources said.

No group or individual has claimed responsibility for the attacks.

Violence is still common in war-torn Iraq despite the dramatic decrease since its peak in 2006 and 2007 when the country was engulfed in sectarian killings.