A suicide car bomber blew himself up in front of a Baghdad police academy on Sunday, killing 15 people and wounding 21 others in the deadliest attack in the Iraqi capital in weeks, security officials said.

At least eight other people were killed in attacks elsewhere in Iraq.

The suicide bomber "blew himself up at the entrance of the police academy on Palestine Street," an interior ministry official said, putting the toll at 15 dead and 21 wounded. A police colonel confirmed the toll.

The ministry official told AFP the assailant was at the wheel of a car rigged with explosives and that most of the victims were students applying to join the police force.

One police officer who was hit in the leg by shrapnel from the blast told AFP at the Ibn al-Nafis hospital that the explosion occurred near the back entrance of the academy when he and others were leaving.

"We finished our duty and we were walking outside, and suddenly we felt a strong explosion," said the officer, who spoke on condition of anonymity.

He said he saw damaged civilian and police vehicles at the scene.

Security forces armed with Kalashnikov assault rifles were deployed on the street where the bombing occurred, preventing most cars from entering, as a truck sprayed water on the site.

Tow-trucks dragged the burned-out remains of two cars down the street and off through traffic, leaving behind another damaged car that was missing most of its windscreen. Journalists were not permitted near the bomb site.

It was the deadliest attack in Iraq since January 27, when a suicide bomber detonated an explosives-packed car outside a hospital in Baghdad, killing 31 people.

Also on Sunday, gun and bomb attacks in other parts of the country killed eight people -- four police informants, two policeman and two anti-Qaeda militiamen -- and wounded four others, security officials said.

"A group of suspected Al-Qaeda gunmen attacked a house in the centre of Baquba around 7:30 am (0430 GMT)," said a police major in Baquba, 60 kilometres (37.5 miles) north of the capital.

"The attackers killed three women and one man from one family inside the house," the major said, adding that the victims were all police informants.

In Ramadi, 100 kilometres (60 miles) west of Baghdad, police First Lieutenant Anas Mohammed al-Fahdawi was killed by a sticky bomb, police Major Qassem Mohammed said.

Gunmen in a civilian car also targeted a checkpoint manned by police and anti-Qaeda Sahwa (Awakening) militia members in Abu Khamis north of Baquba, killing a policeman and two Sahwa members, a police lieutenant colonel said.

Two Sahwa members were wounded in the attack, he added.

Two more Sahwa members were wounded by a roadside bomb near Samarra, 110 kilometres (70 miles) north of Baghdad, a lieutenant colonel in the Samarra police said.

The Sahwa are made up of Sunni tribesmen who sided with the US military against Al-Qaeda from late 2006, helping to turn the tide of the insurgency.

Police also found the burned body of the criminal court judge Abdelrizak al-Qubaisi in his house in Al-Qaim, 340 kilometres (210 miles) west of Baghdad, Lieutenant Colonel Mohammed al-Akili of Al-Qaim police said.

And the interior ministry said on its website that the bodies of a man and a woman who had been shot in the head were found in Sadr City in north Baghdad. It was unclear when they were killed.

Violence in Iraq is down from its peak in 2006 and 2007, but attacks remain common, and 151 people were killed in violence in January.