BAGHDAD, Jan. 13 -- At least 12 people were killed and 55 others wounded in violent attacks across Iraq on Monday, most of them in the capital city of Baghdad, police said.

A car bomb attack killed five people and wounded 14 others in Bab Almuadem area of northern Baghdad, a police source told Xinhua.

Two people were killed and 13 others wounded in a car bomb in Shulla area of northeastern Baghdad, while a third car bomb killed one person and injured 10 others in Shab district also in the northeast of the capital, the source said.

He noted that one person was killed and nine others were wounded in a car bomb in al-Adhamiya area of northern Baghdad.

In the town of Madain, just 30 km south of Baghdad, two policemen were killed and six others wounded in an attack on their checkpoint, the source said.

Also in the day, one policeman was killed and three others were wounded in an attack on their checkpoint in northern Tikrit, some 170 km north of Baghdad, a local police source said.

Iraq is witnessing its worst violence in recent years. According to the UN Assistance Mission for Iraq, a total of 8,868 Iraqis were killed and more than 18,000 others wounded in 2013.