At least 28 bodies of police recruits have been discovered in two areas of the Iraqi capital, Baghdad.
The blast outside the Mustansiriya University killed five
The bodies of 15 young men were found in a truck in Abu Ghraib on the western outskirts of the city on Sunday, according to police.
The rest were discovered in the district of Baghdad. All had been shot, officials said.
Meanwhile on Monday, a series of car bomb attacks in Baghdad left at least eight people dead and dozens injured.
There were seven attacks in all, the most deadly of which was a double car bombing near the Mustansiriya University in the east of the city in which five people died and 25 were injured.
Another blast near the health ministry, apparently targeting a police patrol, left three people dead and 25 injured, including several policemen - two of whom had been directing traffic.
A police spokesman said at least three other cars were destroyed and some shops had their windows blown out.
In other attacks:
- Eleven people are hurt in an attack in central Baghdad apparently targeting a US military convoy, the Associated Press news agency reports
- Two bombs in cars parked near to Iraqi police patrols injure six in the New Baghdad area of the city, AP says
- A car bomb explodes in the Mansur area of the city injuring seven people.
The bodies of the 15 recruits discovered in Abu Ghraib showed signs of torture, AP quoted Lieutenant Colonel Faleh al-Mohammedawi as saying.
Iraqis hope Mr Maliki's new government will bring stability
The men were from the town of Ramadi, 115 km (70 miles) west of Baghdad.
Insurgents in Ramadi have been warning fellow Sunnis against joining the police and army.
Ramadi has been an insurgent stronghold for many months.
The latest violence came as the new PM-designate Jawad Maliki prepared to hold talks on forming a national unity government.
Mr Maliki has 30 days to form a government after being endorsed as prime minister by parliament.
Mr Maliki told state television he hoped to have a new government in place within two weeks.
Correspondents say all sides hope a national unity administration will contribute to reducing the violence in Iraq.