Two police officers have been found dead in central Indonesia, a week after they disappeared while investigating suspected terrorist activities, authorities said Wednesday.

National police spokesman Col. Agus Rianto said the officers' bodies were found Tuesday with their throats slit and stripped of almost all their clothes in a shallow grave in mountainous Poso district of Central Sulawesi province, the site of deadly religious clashes a decade ago.

"They apparently were tortured before being killed," Rianto told a news conference.

He refused to say who might be involved, but another police spokesman, Brig. Gen. Boy Rafli Amar, said some members of Jemaah Anshorut Tauhid, an organization founded by convicted radical cleric Abu Bakar Bashir and designated a terrorist group by the U.S. in February, were involved in the deaths.

"There is more than one perpetrator and they are well trained," Amar said, adding the guns of the officers were taken.

Rianto said the two had been missing since Oct. 8, a day after police arrested a suspected militant who tipped them off to a possible terrorist training camp in Poso, where clashes between Christians and Muslims left more than 1,000 people dead between 2001 and 2002.

Indonesia, a secular nation, has been battling terrorists since 2002, when militants linked to the Southeast Asian network Jemaah Islamiyah began attacking Western nightclubs, restaurants and embassies. More than 260 people have been killed in the attacks, many of them foreign tourists.

Recent terror attacks in Indonesia have been carried out by individuals or small groups and have targeted security forces and local "infidels" instead of Westerners, with less deadly results.