BAGHDAD, Aug. 29 (Xinhua) -- Three policemen and a civilian were killed in separate attacks in Iraq's eastern province of Diyala, a provincial security source said on Wednesday.

In one attack, unidentified gunmen opened fire on a car carrying two police officers and killed them while driving on a main road in Udheim area in north of the provincial capital Baquba, some 65 km northeast of Baghdad, Major Khalil al-Timimi from Diyala Operations Command told Xinhua.

Separately, a policeman was killed in a roadside bomb attack near the village of Mkheisa, some 95 km northeast of Baghdad, Timimi said.

Also in the province, Islamic State (IS) militants kidnapped a civilian late on Tuesday night in the village of Bahiza, some 145 km northeast of Baghdad, and killed him later at the edge of the village, Timimi added.

The security situation in Iraq has been dramatically improved after Iraqi security forces fully defeated the extremist IS militants across the country late in 2017.

However, small groups and individuals of extremist militants melted or regrouped in urban and rugged areas, and are carrying out attacks against the security forces and civilians despite operations from time to time to hunt them down.