MANILA, Philippines (AP) _ The Philippine national police chief ruled out the involvement of communist rebels in the disappearance of a U.S. Peace Corps volunteer, saying Tuesday the woman may have fallen off a cliff while hiking alone more than a week ago.
Police director Oscar Calderon said there is no indication that Julia Campbell, 40, from Fairfax, Va., was abducted by lawless elements or the communist New People's Army ``because the area has been cleared of insurgents.''
``We suspect she may have fallen off a cliff,'' he said.
He said he has deployed 32 members of the Special Action Force who are familiar with the area and can speak the local language. The group, normally used in counter-insurgency and emergencies, is trained to maneuver in rough terrain, including rappelling down ravines and cliffs.
The military also deployed a canine tracking team to the village of Batad, in Banaue town in Ifugao province, where Campbell was last seen April 8, army Maj. Gen. Rodrigo Maclang said.
Officials promised U.S. Peace Corps Director Ronald Tschetter that there will be no let-up in the search for Campbell.
Tschetter flew by helicopter Tuesday over Batad and later drove to the area, about 160 miles north of Manila, Ifugao provincial police chief Senior Superintendent Pedro Ganir said by telephone.
``Now they have an idea of how difficult the search operation is,'' Ganir said, referring to the deep ravines and forests in the area.
Ganir said Campbell, wearing blue denim jeans, black shirt and a shawl, was last seen buying soda from a local store.
She was only wearing sandals and had bought a bus ticket to return to Manila by April 9, indicating she did not plan on extending her stay or making a long hike to a spot to view the Banaue's famed mountainside rice terraces, he said.
The U.S. Embassy is offering a $10,000 reward for information on Campbell, spokesman Matthew Lussenhop said.
Maclang said there is only a small military presence in the area because the communist insurgency was not a major concern.
The rebels operate in the Philippines' Cordillera mountain region but are not active in urban or commercial centers.
Campbell is one of 137 Peace Corps volunteers currently in the Philippines. She has been teaching English at the Divine Word College in Albay province's Legazpi city, southeast of Manila, since October 2006. She previously taught at a public school in Donsol in nearby Sorsogon province, said Nora Gallano, assistant dean of Divine Word's College of Liberal Arts.
In 1990, the NPA seized Peace Corps volunteer Timothy Swanson and held him for 50 days on central Negros island. He was later released unharmed.
In June that year, the U.S. government ordered the evacuation of Peace Corps workers from the Philippines after receiving intelligence that rebels may try to kill or kidnap them. But by that time, Swanson already was in rebel hands.