Twelve people were killed and 39 wounded in separate attacks across Iraq, including a suicide bombing on Sunday, police said.

In one attack up to five people were killed and 15 wounded before noon when two suicide bombers wearing explosive vests tried to break into the Shiite college of Imam Kadhim in Ur district in the northeastern part of the Iraqi capital of Baghdad, a police source told Xinhua on condition of anonymity.

One of the attackers blew up himself at the entrance of the college while the other one was shot dead by the guards, the source said.

Three policemen were among the killed and four others were among the wounded, the source said.

Earlier, the police put the toll at one policeman killed and nine people wounded by the attack.

In Iraq's Muthanna province, two car bombs went off near a restaurant and on a main road near the provincial capital city of Samawa, some 270 km south of Baghdad, leaving three people killed and 20 others wounded, a provincial police source said.

In Babil province, three people were killed and four others wounded when another car bomb detonated at the al-Asriyah village in north of the provincial capital city of Hilla, some 100 km south of Baghdad, a local police source said.

Elsewhere, an army officer was killed when a sticky bomb attached to his car exploded while he was driving in the city of Saadiyah, some 120 km northeast of Baghdad, a local police source anonymously told Xinhua.

The violence came less than two weeks ahead of landmark parliamentary elections on April 30, the first in the country since the withdrawal of US troops in late 2011.