The Philippine government asked a large Muslim rebel group Wednesday to help secure the freedom of an ailing Irish priest kidnapped by outlaws, as troops surrounded a jungle logging area where he was being held.

The 11,000-strong Moro Islamic Liberation Front pledged to work for the release of 79-year-old Rev. Michael Sinnott, said rebel leader Mohagher Iqbal. It was a rare alliance between the rebels and the government, who clashed just months ago in violence that killed hundreds.

Gunmen seized Sinnott from his house in southern Zamboanga del Sur province Sunday and took him to an old mountain logging camp in nearby Lanao province, military and rebel leaders said.

In Ireland, Foreign Affairs spokesman and Labor Party President Michael D. Higgins issued an emotional appeal for Sinnott's release and asked the abductors to provide the priest, who recently underwent heart surgery, with medicine.

"Anything visited upon him is visited upon everyone in Ireland. For this reason, our Parliament wants to send a message: that we want him released and to have immediate access to the medical support that he requires," Higgins said in a statement.

The military has not ruled out the possibility that the abductors could be Muslim rebels who disobeyed a guerrilla edict prohibiting ransom kidnappings and other acts of banditry, said regional military commander Maj. Gen. Benjamin Dolorfino.

An investigation showed that a notorious pirate in Zamboanga del Sur, Guingona Samal, provided the speedboat used to spirit away Sinnott to Lanao, Dolorfino said.

He said the military would relay intelligence and other details to the Moro rebels.

Sinnott was being held near Sultan Naga Dimaporo township, where Moro guerrillas keep a heavy presence, he said. Getting the rebels to cooperate will ensure the safety of Sinnott and avoid accidental clashes between them and troops, Dolorfino said.

"He's very frail because of a recent heart surgery," Dolorfino told The Associated Press. "We will exhaust all peaceful means to get him, although there is always that last military option."

The rebels and the government just a few months ago were engaged in major clashes that killed hundreds and displaced more than half a million people in the country's south, scene of a decades-old Muslim separatist rebellion in this predominantly Roman Catholic nation.

A truce eased the fighting, and the government used a joint cease-fire committee to ask the Moro rebels for help in ending the latest hostage crisis in the southern Philippines.

Efforts to contain the kidnappers in one area now involved hundreds of army troops. Their aim is preventing the abductors from handing over Sinnott to the Abu Sayyaf extremist group, Dolorfino said.

The 400-strong Abu Sayyaf has been suspected of getting funds and training from Al Qaeda and has been blamed for deadly bombings, beheadings and kidnappings of foreigners, including priests.