Violence in Iraq killed 21 people on Thursday, among them four anti-Al-Qaeda fighters and an AFP journalist's brother, officials said.

In Samarra, north of Baghdad, gunmen killed two Sahwa anti-Al-Qaeda fighters in an attack on a checkpoint, while two more died in a similar attack near Baquba, also north of the capital.

The Sahwa, who joined forces with the United States from late 2006 and helped bring about a sharp reduction in violence in Iraq, are frequently targeted by Sunni militants, who consider them to be traitors.

In Ramadi, a city west of Baghdad, gunmen killed Zuhair Shallal, the brother of AFP journalist Azhar Shallal.

Northeast of Baquba, a roadside bomb killed two police and wounded a third when it exploded near their patrol in the town of Muqdadiyah, which has been hit by frequent bombings and shootings this year.

And in Baghdad itself, bombings killed three people and wounded 11, while the owner of a tyre shop was gunned down.

Police also found the corpse of a man with signs of torture and gunshot wounds. He was believed to have been killed on Thursday.

In the northern province of Kirkuk, gunmen shot one person dead, while security forces killed eight militants in a multi-province operation that army Staff Lieutenant General Abdulamir al-Zaidi said resulted in the arrest of more than 60 people and the seizure of weapons.

Iraqi security forces have carried out wide-ranging operations targeting militants for more than two months, but have yet to curb the surge in violence plaguing the country.

This year's spike in violence, which has included a number of sectarian attacks, has raised fears that Iraq will relapse into the kind of intense Sunni-Shiite bloodshed that peaked in 2006-2007 and killed tens of thousands of people.

With the latest unrest, more than 250 people have been killed so far this month, and over 4,950 since the beginning of the year, according to AFP figures based on security and medical sources.