MOSUL: A suicide bomber attacked an Iraqi army convoy in the northern city of Mosul early on Monday, killing at least 22 soldiers and three passers-by, police said.

The bomber drove a vehicle packed with explosives up to a military convoy in the eastern Kokchali district of Mosul, 390 kilometres north of Baghdad, before blowing himself and his car up.

“A suicide bomber was following the convoy and when it stopped in the middle of road, he detonated his vehicle right behind it,” said a policeman at the scene who declined to be identified because he was not authorised to speak to the media.

A separate attack in western Mosul killed four policemen, police said.

It was not clear who was behind the blasts, but suicide bombings are the hallmark of Al Qaeda, which has been regrouping in Mosul, Iraq's third-largest city and capital of the Sunni-dominated Nineveh province.

The attacks are the latest in a campaign of violence across Iraq that has raised fears of a return to full-blown conflict in a country where Kurds, Shia and Sunni Muslims have yet to find a stable way of sharing power.

Nearly 600 people have been killed in militant attacks across Iraq so far this month, according to violence monitoring group Iraq Body Count.

That is still well below the height of bloodletting in 2006-07, when the monthly death toll sometimes exceeded 3,000.