"Iraq is witnessing some of its worst violence in recent years."
Baghdad, May 24 - A total of 12 people including four Iranian nationals were killed and 39 wounded in separate attacks across Iraq Saturday, police said.
In Iraq's eastern province of Diyala, four Iranian workers were killed when a roadside bomb struck a convoy of vehicles belonging to an Iranian company building a gas pipeline between Iran and Iraq in Imam Wies area, some 110 km northeast of Baghdad, Xinhua quoted a provincial police source as saying Saturday.
Eight Iranian and Iraqi workers were also wounded in the blast.
The Iranian company was working on extending the pipeline as part of a deal signed earlier with Iraq to import gas into Iraq to fuel a power plant in Mansouriyah area in Diyala province.
No group has immediately claimed responsibility for the attacks.
However, violence and sectarian tensions have been running high during the past few months between Sunni and Shiite communities in the volatile province of Diyala, as Sunnis and Shiites accuse each other of supporting extremists and militiamen.
In a separate incident, four policemen were killed and another wounded by gunmen who attacked a police checkpoint in al-Raga area, just south of the city of Samarra, some 120 km north of Baghdad.
In Anbar province, four people were killed and 19 others wounded by artillery and mortar shelling on several neighbourhoods in militant-held city of Fallujah, some 50 km west of Baghdad, a medical source said.
Also in the province, a car bomb went off near the government compound of the city of Haditha, some 200 km west of Baghdad, leaving three policemen and five civilians wounded, a provincial police source said.
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.
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.