Baghdad - Two sisters in the northern Iraqi city of Mosul were among a dozen civilians killed in Iraqi violence on Wednesday, which included two bomb attacks in the capital Baghdad.

An unidentified gunmen shot and killed one of the two sisters in front of her house while she was waiting for the bus and then stormed the house and opened fire on the family, killing the other sister and injuring their mother, who was rushed to a nearby hospital for treatment," the Voices of Iraq (VOI) news agency quoted a police source as saying.

The gunmen planted a bomb inside the house which went off injuring three policemen who entered the house after the killings.

The family were Christians, who as a group in Mosul have been subjected to killings and death threats since September, and many thousands have fled the city.

Baghdad was the scene of two bombings. A car bomb in al-Nasr square in the city's centre killed nine and injured dozens, al- Arabiya TV reported, while in north-eastern Baghdad, nine civilians were injured, including two women, when a bomb struck their minibus in Shab district, a police source told VOI.

In the northern city of Kirkuk, one civilian was shot dead and four injured by a man wearing an Iraqi Army uniform, police sources in the city said.

In other news, the Iraqi government on Wednesday nominated Prime Minister Nuri al-Maliki for the Nobel peace prize for his efforts in sustaining peace in Iraq, the Iraqi national information centre said in a statement. (dpa)