Manila  - Philippine President Gloria Macapagal Arroyo ordered an investigation into the killing of the daughter of a senior communist rebel leader, an official said Saturday.

Arroyo wanted the killers of Rebelyn Pitao, 20, to be immediately brought to justice, Press Secretary Cerge Remonde said.

Pitao was a daughter of Leoncio Pitao, also known as Commander Parago, of the New People's Army, the armed wing of the Communist Party of the Philippines.

Her body was fished out of a river late Thursday in Carmen town in the southern province of Davao del Norte, 975 kilometres south of Manila, a day after she was abducted by unidentified gunmen in nearby Davao City.

Police investigators said Pitao's body bore signs of torture.

"The president has ordered an investigation into the reported killing of the daughter of Commander Parago," Remonde said. "The state also recognizes that is a violation of human rights. Those responsible for that should be punished."

The victim, a teacher, was riding in a tricycle on the way to her home in the village of Bago Gallera in Davao City when gunmen aboard a van blocked the tricycle and dragged her into the vehicle.

Pitao's family blamed the military for Rebelyn's death, saying she had no enemies who would have a motive to abduct and kill her.

A local human rights group also alleged that the military has been targeting Parago's relatives to get to the rebel leader. It noted that in June, a younger brother of Parago was shot dead by suspected government forces in Tagum City, also in Davao Del Norte.

Investigations by local and international human rights groups, including the United Nations, have noted the involvement of some soldiers in attacks against leftist activists.

Communist guerrillas have been fighting the Philippine government since the late 1960s, making the movement one of the longest-running leftist insurgencies in Asia. (dpa)