At least 27 people were killed and 129 others wounded in a series of car bomb explosions across the Iraqi capital of Baghdad on Monday, sources said.

A total of 12 car bombings ripped through nine districts in Baghdad, an interior ministry source told Xinhua on condition of anonymity.

An earlier report said that five car bombs went off in Baghdad, killing 13 people and wounding 55.

Three people were killed and 10 wounded when a car bomb went off in the Shiite bastion of Sadr City district in eastern Baghdad, the source told Xinhua.

Another car bomb was detonated in the southeastern New Baghdad district, killing two people and wounding 11 others, the source said.

Four more people were killed and 12 wounded in a car bomb in Baghdad northern district of Kadhmiyah.

Meanwhile, a car bomb exploded in the northern suburb of Sabie al-Bour, killing three people and wounding 13, he added.

A fifth car bomb struck the eastern al-Baladiyat district and killed a civilian and wounded nine.

The toll could rise as ambulances and civilian cars evacuated the victims to different hospitals and medical centers in the city, the source said.

The attacks came a day after a wave of insurgent attacks killed 55 people and wounded some 135 others across Iraq.

Iraq is witnessing its worst eruption of violence in recent years, which raises fears that the country is sliding back to the full-flown civil conflict that peaked in 2006 and 2007, when monthly death toll sometimes exceeded 3,000.

The UN Assistance Mission for Iraq said earlier this month that almost 5,000 civilians were killed and 12,000 others injured in Iraq from January to August.