(3RD UPDATE) THE military on Tuesday said the Department of Environment and Natural Resources (DENR) contractors abducted last May 30 and released on June 2 have undergone post-traumatic stress debriefing in Davao City.

"They are now at the DENR Regional Office for stress debriefing," Captain Alberto Caber, Eastern Mindanao Command spokesperson, said.

He added that the four contractors along with their driver were turned over to Davao City Mayor Rodrigo Duterte on Monday afternoon.

Caber said that the DENR contractors were released in Barangay Panangan-Sangab, Maco town, Compostela Valley province.

Armed Forces of the Philippines (AFP) Public Affairs Office (PAO) chief Lieutenant Colonel Ramon Zagala identified the contractors as Kendrick Wong, Nico Lasaca, Chris Favila, Tim Sabino and driver Jonas Loredo.

Aside from Duterte, Zagala said Davao Vice Mayor Voltaire Rimando also negotiated for their safe release the abducted civilians.

“In behalf of the Department of Environment and Natural Resources, our sincerest thanks to Mayor Duterte for his help in freeing the Skyeye personnel without any condition,” said Environment Secretary Ramon Paje in a statement.

On Monday, the New People's Army acknowledged detaining the five civilians as they were mistaken for government troops conducting aerial survey using a sky-eye drone or an unmanned aerial vehicle (UAV).

Zagala criticized the communist rebels' "paranoid move."

"Contrary to what the NPA is claiming, the civilians were there to bring services to the people by undertaking validation and survey on the government's National Greening Program in the area," Zagala said in a statement.

"The NPA resort to hostage-taking, abduction and detention on anything that can compromise their disposition. These are criminal acts and violation of the human rights that continue to endanger lives of innocent civilians," said the military official as he assured that the AFP will continue its operations against illegal activities allegedly perpetrated by the NPA, particularly in the Davao area.

Meanwhile, DENR regional director Joselin Marcus Fragada earlier apologized to the local authorities of Maco, Compostela Valley for non-coordination with the local government unit prior to the conduct of the aerial survey in Barangay New Leyte.

Fragada said the activity of the survey inspectors from Manila-based Sky Eye UAV, which was commissioned by the Provincial Environment and Natural Resources (Penro), was not also coordinated with the DENR, thus he only knew that the surveyors were in the area when he was informed of the abduction last Friday.

He said the surveyors are independent contractors and not part of the DENR. They are young graduates from the Ateneo de Manila University who ventured into such business.

Fragada said the group was commissioned mainly for aerial survey to validate the National Greening Program (NGP) tree plantation implemented by the government three years ago.

The NGP is one of the flagship programs of the National Government to have 1.5 million hectares planted to trees. In the region, a total of 33,000 hectares were already planted with different tree species, including cacao, coffee and Falcata.

Under the NGP program, the DENR is required to produce geo-tag photos from the ground. And they also need to match these photos with an aerial/satellite surveillance to make sure that tree plantations really exist and to check survival rates of the tree seedlings.

He said the use of drones is one way to get an aerial surveillance.

Fragada pointed out there was no malicious intent in the use of drones.

However, he admitted there were lapses in the area of coordination that even DENR Davao Region office has no knowledge of the group's presence in the area.

"Using this (drone) technology will prevent the occurrence of ghost sites/projects and ensure that investment of government will be protected. It will also ensure accountability of DENR officials in the field," Environment Secretary Ramon Paje said. (PNA/Third Anne Peralta/Virgil Lopez/Sunnex)