ZAMBOANGA - An elderly Irish priest kidnapped in Zamboanga del Sur was seen alive in an area known to be a stronghold of Muslim militants, a military official said Tuesday.

Michael Sinnott, 79, and his heavily armed captors were seen Monday in a coastal area of Lanao del Sur province about 70 kilometers (43 miles) southeast from where he was taken, regional military chief Major General Ben Dolorfino said.

"The victim and his kidnappers were sighted in Lanao del Sur," Dolorfino told reporters, but declined to give specific details so as not to jeopardize pursuit operations.

He declined to elaborate when asked why troops were not immediately sent in to rescue Sinnott, who was seized by six armed men Sunday from his home at the Missionary Society of St Columban compound in Pagadian city on Sunday.

Dolorfino also gave no details about Sinnott's health, after the priest's colleagues said a heart problem meant he may not survive the ordeal, and only expressed hope his abductors would treat him well.

"We cannot say anything about his condition but we know he recently underwent bypass surgery and considering that situation (we hope) his captors may not move him around to different places," Dolorfino said.

Authorities have said the Al Qaeda-linked Abu Sayyaf or the separatist Moro Islamic Liberation Front (MILF) are suspects. Both groups, as well as other unnamed Muslim armed gangs, are known to operate in parts of Lanao.

The MILF and the Abu Sayyaf are striving for an independent Muslim homeland in the south of the mainly Catholic Philippines.

The MILF on Tuesday denied involvement and said it was willing to help recover Sinnott. "We are not involved in this, and we see no reason why our men should be involved in this," MILF spokesman Eid Kabalu said, stressing that his group was set to resume peace talks with the government.

The 79-year-old Catholic priest, whose health has been fragile since heart surgery last year, was seized by 6 armed men from his home at the Missionary Society of St Columban compound in Pagadian city on Sunday.

Police and the military said either the MILF or the smaller Al Qaeda-linked Abu Sayyaf group could be behind the abduction, the latest in a long list of kidnappings targeting foreign missionaries and tourists in the south.

"We don't know who is behind this, but what is important is that we are willing to cooperate and assist the government look for him (Sinnott) for humanitarian reasons," Kabalu insisted.

He noted that, as a confidence-building mechanism, the MILF had in the past helped the government track down wanted criminals on Mindanao island.

MILF commanders on the ground have been told to report any sightings of Sinnott and his abductors and to coordinate quickly with the rebel leadership, which will then relay the information to government negotiators, Kabalu said.

"The abduction appears to have been planned, and carried out surgically," Kabalu said.