Thirteen people were killed and 15 others wounded in separate violent attacks across Iraq on Monday, police said.

In northern Iraq, Iraqi soldiers shot dead two gunmen who were trying to plant a roadside bomb in the northern part of the city of Mosul, a local police source told Xinhua on condition of anonymity.

In a separate incident, a booby-trapped car went off at an intersection in eastern Mosul, leaving a civilian killed and five others wounded, the source said.

Also in Mosul, a soldier and a policeman were killed in two attacks by gunmen, while a roadside bomb struck a police vehicle in the city and wounded an officer and two policemen, the source added.

Elsewhere, gunmen attacked a checkpoint manned by members of a government-backed Sahwa paramilitary group in the city of Hawijah, some 220 km north of Baghdad, killing three group members and wounding two others, a local police source said.

The Sahwa militia, also known as the Awakening Council or the Sons of Iraq, consists of armed groups, including some powerful anti-US Sunni insurgent groups, who turned against the al-Qaida network after the latter exercised indiscriminate killings against both Shiite and Sunni Muslim communities.

In Salahudin province, four policemen were wounded when gunmen opened fire on them in the provincial capital city of Tikrit, a provincial police source told Xinhua.

In another incident, a police officer and two policemen were killed when gunmen attacked a police station at a village near the town of Seniyah, some 50 km north of Tikrit, the source said.

Also in the province, a government employee was shot dead when gunmen attacked his car in Hajaj area north of Tikrit, while a driver of a government vehicle was killed by gunmen in the city of Shirqat, some 110 km north of Tikrit, the source added.

In Baghdad, a government employee was critically wounded when a sticky bomb attached to his car detonated in Saidiyah district in southern the Iraqi capital, a police source said.

Iraq is witnessing its worst violence in recent years. According to the United Nations Assistance Mission for Iraq, a total of 8,868 Iraqis, including 7,818 civilians and civilian police personnel, were killed in 2013, the highest annual death toll in years.