Headless Bodies Found in Philippines

Two headless bodies discovered in the Philippines are not believed to be Americans despite claims by a Muslim rebel group to have beheaded a U.S. hostage they've held since last month.

A senior U.S. official told ABCNEWS that sources in the Philippines had seen a videotape of a beheading, but it was not immediately clear who the victim was.

The Abu Sayyaf, said by the U.S. government to be the smallest and most radical of Islamic separatist groups in the Philippines, claimed earlier today to have beheaded Guillermo Sobero, one of three Americans it has been holding since last month.

But neither body was that of an American, National Security Adviser Roilo Golez told Reuters, adding that both men were Filipino volunteer negotiators.

At a press briefing today, State Department spokesman Philip Reeker, however, could confirm only that one "torso" was found and said U.S. authorities were not certain it was not that of Sobero.

"We need to allow time for the appropriate forensics examinations," he said.

Hostages Not Killed Previously

The Abu Sayyaf, which split off from another group in 1991 and operates generally in the southern Philippines, has kidnapped more than 30 foreigners in its history. But it has never before killed a foreign hostage despite many threats to do so, though it has engaged in bombings and assassinations.

The claim by the group that it beheaded Sobero, a 40-year-old California native, has attracted widespread condemnation in the international community.

One of the bodies was discovered on the opposite side of Basilan Island in southern Philippines to where the Abu Sayyaf claimed to have killed Sobero. A second body was discovered a short time later.

Although there were no U.S. teams on the ground and officials still held out the hope that the Abu Sayyaf claims were false, there were growing concerns that the guerrilla group did indeed carry out beheadings.

"I'm still hoping this is not true, and I'm holding on to that belief," Sobero's younger brother, Alberto, told The Associated Press from his home in Cathedral City, near Palm Springs.

A Chilling Call

Tensions have been high following a telephone call to a local radio station earlier today by Abu Sabaya, a spokesman for the guerrilla group.

"We've released unconditionally one American, our amigo Guillermo [Sobero], but we released him without a head," Sabaya told Radio Mindanao Network, according to The Associated Press.

Sabaya said they beheaded the American "because the Philippine government is toying with us."

Sobero, from Corona, Calif., along with Martin and Gracia Burnham, two missionaries from Wichita, Kan., and 17 others were taken from a posh resort on the Sulu Sea on May 27.

Sabaya called the killing a gift to the nation on its independence day, which is being celebrated today. He added that government troops should search for the headless body before it is eaten by dogs.

‘A Cowardly Act’

The U.S. Embassy in Manila condemned what it called "a cowardly act" if Sobero had been killed.

"The murder of an innocent person is a cowardly act. We condemn in the strongest possible terms this reported action," it said in a statement. "We hold the Abu Sayyaf group responsible for the safety and welfare of all of the people it is holding … We call for the safe, immediate and unconditional release of the innocent persons being held."

Equally strong was the reaction from the Philippines government. Almost shaking with anger, President Gloria Macapagal Arroyo lashed out at the group during a reception for foreign diplomats in Manila.

"It is a merciless, ruthless group that has no qualms at all in murdering an innocent person for the sake of ransom money," she said. "The reported murder of Mr. Sobero only strengthens our resolve to decimate once and for all this cold-blooded group."

State Department spokesman Reeker today reiterated the U.S. policy against paying ransom money.

The Abu Sayyaf has so far made no public demands other than to ask for its choice of a hostage negotiator.

Weekend Death Threat ‘Postponed’

The Abu Sayyaf on Thursday had threatened to behead at least one of their American captives if Manila did not appoint its choice of negotiators and call off a military manhunt within 72 hours.

That threat was called off — "postponed," the rebels said — when Arroyo accepted Malaysian statesman Sairin Karno as a member of the team negotiating the release of the hostages.

"If Mr. Sairin can really help, we have no objections to this," presidential spokesman Rigoberto Tiglao said. "We just want to show our sincerity in order to end this crisis and ensure the safety of these innocent victims."

But Manila refused to call off the thousands of troops scouring Basilan island for them. Basilan, 560 miles south of Manila, is only 30 miles long and 19 miles wide.

"We don't believe that at this point, if we stop our military operation, things will come out well, and the hostages will just walk free if forces are removed," military spokesman Brig. Gen. Edilberto Adan said.

Government troops have engaged in fierce fighting with fast-moving rebel units. While the Abu Sayyaf is believed to have only about 1,000 fighters, they are believed well-armed — having purchased weapons, according to some reports, with money from the government paid as ransom in previous kidnappings.

More Hostages, More Problems

On Monday, Abu Sayyaf guerillas stormed a coconut and coffee plantation in southern Basilan and took 15 more hostages, including two 12-year-old children.

The rebels also burned down five houses and a chapel. After a series of escapes, executions and new seizures, the rebels now hold a total of 28 hostages.

The Abu Sayyaf say they are fighting to carve out an independent Islamic state from the southern Philippines, but the government describes them as bandits.

Muslims are a minority in the mostly Roman Catholic Philippines but are a majority in the islands where the Abu Sayyaf operates. ABCNEWS' Mark Litke and Martha Raddatz contributed to this report.