The U.S. Peace Corps volunteer whose body was found buried in a shallow grave in a northern Philippine tourist town appeared to have been bludgeoned and a manhunt for a suspect has been launched, the national police chief said Friday.

Julia Campbell's body was found Wednesday, 10 days after she went missing during a solo hike in the village of Batad in Banaue township to see the area's famed mountainside rice terraces.

"We have found a piece of wood in the vicinity of the suspect's house. We believe this was the instrument used in hitting Julia," police Director General Oscar Calderon told DZMM radio. He said police found what appeared to be bloodstains on the wood.

"There is a semblance really of foul play and that she is a victim because she was buried," he said. "The manhunt is under way."

Campbell's face appeared to have been injured by blows from a hard object, Senior Superintendent Pedro Ganir, police chief of Ifugao province, which includes Banaue, told The Associated Press.

He declined to give other details pending forensic tests.

Ganir earlier said investigators were looking into "robbery with homicide or rape with homicide" — common motives when women disappear in the country — but he said he had no evidence without an autopsy.

Police said the autopsy will be conducted Saturday. U.S. military forensic experts will be flying to Manila from Maryland to observe the procedure, the U.S. Embassy said.

Police were focusing on a male suspect who lived in Batad and may have been related to the masseuse Campbell had scheduled an appointment with on the day she disappeared, according to The Manila Times and other news reports.

Police suggested the man they're zeroing in on could be the husband of the masseuse, and might have been someone Campbell knew. Though he has disappeared from his home, they said they had his name and information on his whereabouts, but declined to release specifics so as not to compromise the investigation.

A 10-year-old boy who police said was "physically present" when Campbell was killed led them to the suspect because he saw the man loitering near where her body was found, according to the Times.

The child also apparently saw the man carrying a backpack that looked like Campbell's after she vanished.

Authorities said they needed more evidence for their case before they could file charges against the suspect.

Troops found Campbell's body in a dry creek, covered with soil, gravel and grass. Police said a dog had dug out one of her feet by the time soldiers located her.

Authorities also discovered a box with Campbell's money, sandals and a transportation ticket near where her body was lying, the Times reported.

Campbell’s body was taken to Loyola Memorial Chapels in Makati City, the Philippines, on Thursday and would remain there pending the results of the autopsy — which could take up to nine days, according to news reports.

Campbell — a journalist who had worked for The New York Times, FOXNews.com, ABCNews.com and other media organizations — was among 137 Peace Corps volunteers now in the Philippines. She had been teaching English at the Divine Word College in Albay province's Legazpi city, southeast of Manila, since October 2006.

She also helped launch an ecology awareness campaign and build an Eco Center in Donsol in Sorsogon province, famous for whale sharks.

Annie Lledo, head of Divine Word's English department, said the school staff, students and teachers could not hold back tears during a Mass for Campbell late Wednesday.

"When she did not show up on April 11 ... to serve as one of the usherettes during the graduation ceremonies, everybody concluded that something was wrong. Julia never abandons her duties," she said.