The Philippines deployed soldiers and gunboats Tuesday to surround the strongholds of suspected Muslim militants and pressure them to release an abducted Irish priest.

Regional military commander Maj.-Gen. Benjamin Dolorfino said a rescue attempt for Rev. Michael Sinnott is not imminent, due to concern for the priest's safety.

Late Sunday, Sinnott, 78, was abducted him from the garden of his residence in the country's volatile south.

Six gunmen dragged the missionary into a van in front of his horrified aides inside the Columban House compound in Zamboanga del Sur province, about 780 kilometres south of Manila.

Dolorfino said the priest was seen Tuesday with his captors in the mountains near the coast, close to a stronghold of the Moro Islamic Liberation Front, the largest Muslim rebel group in the Philippines.

While no group has claimed responsibility for the abduction, the Moro rebels or the more violent Abu Sayyaf group are suspected.

Dolorfino said Sinnott was apparently abducted for ransom.

"I'm sure [the abductors will] take care of him," Dolorfino said. "They see dollar signs on his face."

At least four naval gunboats and army troops were sent to box in the kidnappers.

"We're trying to contain them in one area, to be in a position of strength," Dolorfino said.

Sinnott's health is a concern, as he had heart surgery last year and requires medicine regularly.

While the Philippines is a predominantly Roman Catholic country, the southern regions have witnessed Muslim separatist unrest for decades. Muslims are a minority in the southern Philippines.