The presidential palace expressed apprehensions over the motives of Malaysian politicians who have volunteered to negotiate with Abu Sayyaf rebels in southern Basilan for the release of dozens of hostages.

Rigoberto Tiglao, spokesman for President Gloria Macapagal-Arroyo, said they have received phone calls from people identifying themselves as former Malaysian Senator Sairin Karno and businessman Yusuf Hamdan.

The callers, he said, claim to have established contact with the Basilan-based Abu Sayyaf. Hamdan is known to have links with Muslim separatist groups operating in the region while Karno played negotiator with the Sulu-based faction of the Abu Sayyaf last year when the group took 21 mostly foreign hostages from a resort in Malaysia.

"We appreciate his (Karno's) help, but are a bit worried if he's doing it for the sake of Muslims or for other reasons," Tiglao said, adding: "We are not too happy about it."

The Arroyo administration has remained firm in refusing to negotiate with the Abu Sayyaf, a separatist group operating in Basilan and nearby Sulu, which has resorted to kidnapping to finance its operations and air its grievances against the Manila-based central government.

The families of several hostages who had been taken on May 27 from a resort in western Palawan have been reported to have paid the Abu Sayyaf ransom for the release of their relatives. Aside from this, there were also earlier reports that Filipino Muslims who are now in Sabah, Malaysia, are helping the Abu Sayyaf in some of its operations, particularly kidnapping for ransom and sea piracy.

Kidnapping and piracy operations by the Abu Sayyaf cover the Sulu Sea area which extends from the Philippines islands of Sulu, Tawi-Tawi and the southeastern portion of the western island of Palawan to Sabah in Malaysia's western seaboard.

Sairin and Hamdan had earlier claimed they have convinced the Abu Sayyaf to free three more hostages even as the group beheaded three of its Filipino captives over the weekend. Security forces, which continue to hunt down the kidnappers have not reported any sighting of the supposed three freed hostages.

The Abu Sayyaf continue to hold two Americans and 21 Filipinos captives. A third American, Guillermo Sobero, is presumed dead by the military. The rebels had earlier claimed that they had beheaded Sobero as an Independence Day present to Arroyo. A total of seven decapitated bodies was found last week.

Two were Filipino workers from a plantation in Tuburan town while three were soldiers captured by the Abu Sayyaf during an encounter. Two others found on Friday have yet to be identified. Meanwhile, government forces continued their search for a 14-year-old girl who was seized by suspected Abu Sayyaf rebels in Basilan's Lantawan town, the military said.

Troops are combing the jungles tracking down guerrillas who abducted Nadzmie Mustafa in the remote village of Matikang. Mayor Tahira Ismael of Lantawan town said Mustafa and her two younger brothers were seized from their home, but guerrillas freed the boys on their way to the mountains.

The military said it is investigating the motive behind the abduction. The military estimates the number of Abu Sayyaf guerrillas in Basilan to be around 1,000 and provincial officials said the Abu Sayyaf has been recruiting young Muslims and promising them a monthly allowance of $600
and weapons.