By Ziad al-Sinjary
MOSUL, Iraq (Reuters) - 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 km (240 miles) 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 authorized 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.
Insurgent groups such as al Qaeda have found willing recruits among Iraq's Sunni minority, which resents Shi'ite domination since the U.S.-led invasion that toppled Saddam Hussein in 2003.
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, Shi'ite and Sunni Muslims have yet to find a stable way of sharing power.
Relations between Islam's two main denominations have been put under further strain from the civil war in Syria, which has drawn in Shi'ite and Sunni fighters from Iraq and beyond to fight against each other.
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.
(Additional reporting by Ahmed Rasheed; Writing by Isabel Coles; Editing by Catherine Evans)