Baghdad, Dec 20 

At least 25 people were killed and 36 injured in Iraq as a number of attacks, including a suicide attack on Shiite pilgrims in Baghdad, were witnessed Thursday, police said.

In the deadliest attack, 17 pilgrims were killed and 35 injured when a suicide bomber blew himself up among a procession of Shiite pilgrims walking on a highway in Baghdad's Doura district, Xinhua reported citing a police source.

The pilgrims were heading to the holy Shiite city of Karbala, some 110 km south of Baghdad, to observe the Arbaeen religious ritual ahead of its climax day next Tuesday.

Arbaeen is the 40th day after the martyrdom anniversary of Imam Hussein, Prophet Muhammad's grandson and the third holy figure for the Shiite Muslim sect, who was killed in the battle of Karbala in 680 A.D, the report said.

In a separate attack, gunmen broke into the house of a leader of a government-backed Sahwa paramilitary group in Abu Ghraib area, some 25 km from Baghdad, and shot him dead along with his wife and their three sons, a police source told Xinhua.

In northern Iraq, a police chief of Nineveh's province, escaped with wounds while one of his guards was killed when his convoy was attacked in Mosul city, some 400 km from Baghdad, a provincial police source said.

In Nineveh province, a policeman was shot dead before his house Shora town, some 40 km from Mosul, a source said.

Elsewhere, another policeman was shot dead by gunmen in Shirqat city, some 280 km from Baghdad, a police source said.

According to the UN Assistance Mission for Iraq, 8,109 Iraqis have been killed in the country from January to November this year.