MANILA, June 13 (Reuters) - Roman Catholic and Muslim religious leaders appealed to Islamic rebels on Wednesday to free an Italian priest kidnapped in the southern Philippines, as the army said there had been no sightings of the abductors.

Giancarlo Bossi, a 57-year-old member of the Pontifical Institute for Foreign Missions, was taken at gunpoint by Muslim gunmen after saying mass at a village in Zamboanga Sibugay province on Sunday.

Security officials blamed a rogue faction of the Moro Islamic Liberation Front (MILF), the largest Muslim rebel force talking peace with the government, for the abduction although no one has yet claimed responsibility.

"We have continuously prayed for the conversion of hearts of those responsible for the abduction of Father Bossi," Monsignor Pedro Quitorio, spokesman of the influential Catholic Bishops' Conference of the Philippines, told reporters.

Muslim leaders condemned the kidnapping as a "dastardly act against the morality of Islam".

Sultan Maguid Maruhom, head of a Muslim non-governmental organisation involved in an inter-faith dialogue with Christian groups, said the kidnapping could affect ongoing peace negotiations between the MILF and the government.

"All of these efforts are threatened by this single despicable act of abduction of an innocent religious man who has not wronged anybody else," Maruhom said in a statement.

"We appeal to the perpetrators of this crime to immediately release Father Bossi unharmed."

Security forces have used helicopters and a spy drone to search for the gunmen in the jungles of the southern Philippines but to no avail.

Army spokesman Lieutenant-Colonel Bartolome Bacarro said extra troops, helicopters and navy boats had been sent to the area to prevent the gunmen from taking the priest to Basilan island, the hideout of Abu Sayyaf, the country's smallest but deadliest Islamic militant group.

"We have no sightings, no contact and no information on the priest and the people who took him," Bacarro told reporters.

The MILF has been negotiating to end nearly 40 years of conflict in the Muslim south of the mainly Roman Catholic nation that has killed more than 120,000 people and displaced 2 million.

Talks, brokered by Malaysia since March 2001, have been stalled since September 2006 over the size and wealth of a proposed ancestral homeland for 3 million Muslims.

Government and rebel leaders were confident informal talks would resume soon after Manila asked for postponement of scheduled meetings in Kuala Lumpur on May 1-2 due to local and congressional elections last month.

AlertNet news is provided by