TIKRIT: A suicide bomber wearing a vest packed with explosives killed an Iraqi counter-terrorism official on Monday as he left university in the city of Tikrit after sitting an exam, police said.

The attack killed Colonel Ghazi Ali al-Jubouri, head of counter-terrorism for Salahuddin province, and also wounded two of his bodyguards outside the law faculty at the university of Tikrit, the hometown of former Iraqi dictator Saddam Hussein.

“Colonel Ghazi went to his car in the park. A suicide attacker approached him and blew himself up,” said Salim Ibrahim, an employee at Tikrit university. “Flesh and human remains were hanging from nearby trees and walls”.

Suicide attacks are the signature of al Qaeda's Iraqi affiliate, which has been regaining strength and recruits from among Iraqi Sunnis who feel marginalised following the US-led invasion of 2003 that overthrew Saddam.

Salahuddin's previous counter-terrorism chief was also killed by a suicide bomber while he was shopping in 2009.

Al Qaeda's Iraqi affiliate, the Islamic State of Iraq, claimed responsibility for that attack.

In a separate incident in Mosul, a parked car bomb near an army patrol killed two soldiers and wounded another on Monday, police said.

Al Qaeda and other Sunni insurgent groups have been invigorated by the civil war in neighbouring Syria, which is rapidly descending into a region-wide proxy conflict pitching Sunni Muslims against Shi'ites.

More than 1,000 people were killed in militant attacks in Iraq in May alone, making it the deadliest month since the sectarian bloodletting of 2006-07.