MANILA (UPDATE) - Justice Secretary Menardo Guevarra on Thursday said his department would endorse to the country's inter-agency task group on extrajudicial killings the investigation of the slay of 9 activists in police raids in Calabarzon over the weekend.

In a statement, Guevarra said there is "sufficient evidence" that the slain activists were members of sectoral groups.

"The DOJ (Department of Justice) will endorse the investigation to the AO 35 committee, as there is sufficient evidence that the victims were members of cause-oriented groups carrying out legitimate dissent," he said.

The AO 35 task force is an inter-agency panel intended to probe extrajudicial killings, enforced disappearances, torture and other grave human rights violations involving activists and rights defenders.

The development also came as tensions mounted between the slain activists' relatives and the national police, as authorities have refused to release their bodies despite the families' supposed completion of the documents needed.

On Thursday night, the remains of 4 activists were to be transferred from the Antipolo Memorial Homes to the Philippine General Hospital for autopsy.

WATCH: The bodies of the 4 dead activists are now being loaded onto the vans that will take them to PGH. pic.twitter.com/yV8oxjLpos

— Mike Navallo (@mikenavallo) March 11, 2021

Their relatives showed certification to prove their relationship with the deceased, as required for the release of the bodies.

The massacre happened in raids that police carried out in four provinces in Calabarzon, which also led to the arrest of 4 other people.

The killings have drawn condemnation from rights groups and the international committee, as it came just two days after President Rodrigo Duterte ordered law enforcers to kill armed rebels and "ignore human rights."

More details to follow.

• Philippines tells int'l orgs: Give us chance to probe activist killings

— with reports from Mike Navallo and Job Manahan, ABS-CBN News