[See photo caption below]
ZAMBOANGA, Philippines (AP) - Troops scouring a southern Philippine island for rebels holding some 28 hostages discovered two decapitated bodies Tuesday. Officials said both were Filipinos, including a man who had volunteered to negotiate in the 3-week-old crisis.
The Abu Sayyaf guerrillas said early Tuesday that they had beheaded Guillermo Sobero, one of their three American captives, as a ``gift'' to commemorate the 103rd anniversary of Philippine independence from Spain.
But National Security Adviser Roilo Golez said one of the bodies found on the western part of southern Basilan island was apparently that of a negotiator who contacted the Abu Sayyaf. The second body was apparently unrelated to the ongoing hostage crisis, Golez said.
By Wednesday morning, troops searching the eastern area of the island, where Abu Sayyaf guerrillas said they killed Sobero, had found no sign of his body.
Several hundred reinforcements joined thousands of troops Wednesday to hunt the Abu Sayyaf, who claim they are fighting to create a southern Islamic state.
``Tell Gloria to hurry up and solve this with her rescue operation because you might not have any hostages left,'' guerrilla leader Abu Sabaya tauntingly told the Radio Mindanao Network, making reference to Philippine President Gloria Macapagal Arroyo (news - web sites).
Sobero, 40, a Peruvian-born Californian, was vacationing in the Philippines when he and other tourists were seized from an island resort across the Sulu Sea in late May.
The Abu Sayyaf has refused to free them until the government allows the participation of Malaysian negotiators who helped secure the release of other hostages last year.
The government agreed Monday, but Sabaya questioned the sincerity of the concession and said he beheaded Sobero anyway.
Philippine authorities held out hope Sabaya was bluffing - but seemed increasingly resigned he wasn't. A military intelligence task force put the likelihood Sobero was dead at ``very, very high,'' Armed Forces Chief of Staff Diomedio Villanueva said.
Police Senior Supt. Akmad Mamalinta said Wednesday that 60 rebels were spotted near General Santos city earlier this week, 230 miles west of Basilan island. He said the men, toting machine-guns, bought food from farmers before disappearing into jungle.
Sabaya earlier this week threatened to send out units of fighters to attack several areas of the southern Mindanao region.
The rebel chieftain also threatened to kill Muslim clerics - called ulamas - who criticized the Abu Sayyaf on Monday, saying their activities counter Islam.
``They should be the first in fighting those that oppress us,'' Sabaya said. ``Now they are working together with the government. One day we'll behead the ulamas, too.''
Arroyo denounced the reported beheading and ordered an all-out war against the guerrillas.
``They did this dastardly act to prove that they are not kids making empty threats, underlining the ghoulishness and viciousness of the Abu Sayyaf,'' she said.
Sabaya had been threatening to execute an American at noon Monday but pushed back the deadline when the government gave into his demand that former Malaysian Sen. Sairin Karno be brought in to negotiate.
Sabaya rebuffed the offer Tuesday, telling the military to look for Sobero's head near the town of Tuburan.
``We ... can see that the government wants to outsmart us with these negotiators. What are we, stupid?'' he said. ``So we've cut off negotiations. We will call again when we've beheaded another to let them know.''
Arroyo has offered 2 million for the capture of Abu Sayyaf leaders but has refused ransoms. The millions reportedly paid for the release of hostage last year is believed to have funded the arms and speedboats used in the May 27 raid.
Yellow ribbons adorned the trees in Sobero's neighborhood in Corona, Calif., east of Los Angeles. But only the oldest of Sobero's four children, a 13-year-old daughter, knows her father was kidnapped, his brother Alberto Sobero said in Cathedral City, Calif. ``They think he's on vacation,'' said Neuza Chiong, a cousin of Guillermo Sobero's wife, Fanny. ``I'm not sure when we'll tell them.''
Last year, the rebels executed two Filipino teachers. This is the first time the Abu Sayyaf claimed to have killed a foreigner.
On Monday, the rebels stormed a coconut and coffee plantation, taking 15 new hostages on top of the 13 they were already holding, the army said.
Two American missionaries from Kansas, Gracia and Martin Burnham, are among the captives being held on Basilan island, 560 miles south of Manila.
PHOTO CAPTION

A Filipino boy watches government soldiers searching for Abu Sayyaf rebels in a Lantawan village on Basilan island, June 12, 2001. The Muslim rebels said they had beheaded one of three American hostages held since May, and there were reports than an unidentified human torso had been found. (Erik De Castro/Reuters)