At least 30 people have been killed and more than 90 injured in a series of bombings in Iraq's capital Baghdad.

Police confirmed that nine blasts ripped through crowded marketplaces and other commercial areas in predominantly Shia parts of the city on Sunday.

No one has yet claimed responsibility for the attacks but Sunni Muslim insurgent groups are known to target civilians and security personnel in Shia neighbourhoods in an attempt to undermine Iraq's Shia-led government.

Police said the deadliest of the attacks took place in the mostly Shia district of Baiyaa, where a car bomb exploded inside a car repair shop, killing seven people and wounding 14.

Other bombings hit shops and markets in the areas of Ghadeer, Amil, Sadr City, Hussainiyah and the Sunni area of Radhwaniya, where two people were killed and eight wounded after a bomb hit a row of shops.

Authorities said an off-duty army officer was killed when a sticky bomb attached to his car exploded in the town of Mada'in, south of Baghdad.

Interior ministry spokesman Saad Maan Ibrahim said the attacks bear the hallmarks of al-Qaida's Iraqi branch.

"Al-Qaida terrorists have been attacking soft targets because they are not able to confront our security forces," he said. "They want to send a message that they are still strong."

According to figures released by the Iraqi ministries of health and defence, 948 people were killed in Iraq in November - 852 civilians, 53 policemen and 43 soldiers. Iraq's interior ministry puts the death toll at 1,121.