A total of 66 people were killed in violent attacks and battles between insurgents and Iraqi security forces in the provinces of Anbar and Diyala, security sources said. In Iraq's western province of Anbar, an Iraqi commando force fought fierce clash with gunmen in al-Sijar area in the northern part of the militant-seized city of Fallujah, some 50 km west of the Iraqi capital of Baghdad, leaving 33 militants killed, a provincial police source told Xinhua on condition of anonymity. The army's artillery pounded the industrial district in Fallujah, killing three militants and injuring two others, the source said. Separately, gunmen shot dead a member of a government-backed Sahwa paramilitary group in Abu Ghraib area, some 25 km west of Baghdad, the source added. Anbar province has been the scene of fierce clashes that flared up after Iraqi police dismantled an anti-government protest site outside Ramadi in late December last year. In the country's eastern province of Diyala, anti-government militant groups, suspected to be linked to al-Qaida organization, took control of three districts in the town of Buhruz near the provincial capital city of Baquba, some 65 km northeast of Baghdad, after fierce clashes since late on Saturday night with Iraqi security forces, the source said. The clashes resulted in the killing of 14 militants and three policemen, wounding three policemen, the source said, adding that reinforcement troops are surrounding the districts, while dozens of families left their homes to safer areas in the town of nearby Baquba city for fear of the continuing clashes. Also in Buhruz, a joint army and police force carried out an operation on a suspected al-Qaida safe house and killed a leader of al-Qaida militant group, who was known for his role in killing many security and Sahwa members, the source added. Diyala province, which stretches from the eastern edges of Baghdad to the border in east of the country, has long been a volatile area since the U.S.-led invasion of Iraq in 2003 despite repeated military operations against the militant groups. In Iraq's northern province of Nineveh, three civilians were shot dead by gunmen in separate incidents in the provincial capital city of Mosul, some 400 km north of Baghdad, a provincial police source told Xinhua. In a separate incident, a roadside bomb struck an army patrol in the eastern part of Mosul, leaving two soldiers dead, the source said. Also in the province, a policeman, an off-duty soldier and a civilian were killed in three attacks by gunmen in the areas of Rabiaa and Zummar in the western part of the province, the source added. In central Iraq, a police officer and a policeman were killed and two policemen wounded when gunmen attacked their patrol near a police station in the village of Hajaj, just north of Salahudin's provincial capital city of Tikrit, some 170 km north of Baghdad, a provincial police source anonymously told Xinhua. Separately, a engineer was killed and nine people were wounded in an explosion of a bomb hidden at a waste container in a busy street in Tikrit, the 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, including 7,818 civilians and civilian police personnel, were killed in 2013, the highest annual death toll in years.