BAGHDAD, July 25 (Xinhua) -- A total of four people were killed Wednesday and another was kidnapped in separate incidents across Iraq's eastern province of Diyala, a provincial security source said.

A roadside bomb explosion, planted by Islamic State (IS) militants, in the orchard of a tribal leader at the Zahra Village, some 25 km northeast of the provincial capital Baquba, killed the tribal leader, Colonel Ghalib al-Attya, spokesperson of Diyala provincial police, told Xinhua.

Two more farmers were killed in the same village when gunmen opened fire on them inside their orchard before they fled the scene, Attya said.

The two attacks prompted the security forces to intensify security measures and to launch an investigation into the incidents, Attya added.

Elsewhere in Diyala, IS militants attacked at dawn a village at the edge of the volatile town of Udheim, some 60 km north of Baquba, killing a villager and kidnapping another, he said.

Despite repeated military operations in the Diyala province, remnants of IS militants are still hiding in some rugged areas near the border with Iran, and in the sprawling areas extending from the western part of the province to the Himreen mountainous area in north of Baquba, which itself located some 65 km northeast of the Iraqi capital Baghdad.

On Dec. 9, 2017, Iraqi Prime Minister Haider al-Abadi officially declared full liberation of Iraq from the IS extremist group.

However, small groups of IS militants have since regrouped in rugged areas, carrying out attacks against security forces and civilians despite the military operations from time to time to hunt them down.