BAGHDAD, May 14 -- A total of 31 people were killed and 22 others injured in separate bombings and shootings across Iraq, police and medical sources said on Wednesday.

In Iraq's eastern province of Diyala, gunmen attacked an outpost for a police commando force late on Tuesday night in Udheim area, some 60 km north of the provincial capital city of Baquba, leaving eight commandos killed, a provincial police source said.

Also in the province, security forces carried out a pre-dawn offensive on a camp believed to be used by militants linked to the Islamic State of Iraq and Levant (ISIL), an al-Qaida breakaway group in Iraq, in Himreen area in northeast Baquba, some 65 km northeast of the Iraqi capital of Baghdad, the source said.

During the offensive, at least four ISIL gunmen were killed and a cache of weapons and explosives seized, the source added.

In Salahudin province, gunmen attacked a police patrol early in the morning in the town of Yathrib, some 80 km north of Baghdad, killing two police personnel and wounded three passers-by, a provincial police source said.

Also in Salahudin, two police were killed in a roadside bomb attack on their patrol in central Tikrit, the provincial capital city, some 170 km north of Baghdad, the source said, adding that two more policemen were wounded in another roadside bomb attack in the city.

In Anbar province, government forces killed seven suspected ISIL gunmen in the town of Saqlawiyah, just north of the city of Fallujah, some 50 km west of Baghdad, a provincial police source said.

Meanwhile, seven people were killed and nine wounded by artillery and mortar shelling on several neighborhoods in militant- seized city of Fallujah, a medical source from the city hospital said.

In a separate incident, a suicide bomber blew up an explosive- laden car at a police station in the city of Heet, some 160 km west of Baghdad, wounding four policemen, the source added.

Near Baghdad, police found the body of a young man with a bullet wound in the head in Abu Ghraib area, some 25 km west of the capital, while four civilians were wounded in a roadside bomb blast near their car in the same area, a local police source said.

Iraq is witnessing some of its worst violence in recent years. According to the UN 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.