The American captives of the Abu Sayyaf group, Martin and Gracia Burnham, could be released in Kuala Lumpur before the end of this month, a local radio station said. "This was the plan hatched by the Abu Sayyaf group, to escape arrest," DxRZ-Radyo Agong quoted an unidentified source as saying.

The nearest Malaysian boundary from Basilan, where the group is also holding a Filipina nurse, is "just a four-hour ride by boat", the source added.

Meanwhile, three Philippine Air Force F5 jets were seen flying over Basilan, but officials declined to say what its mission was.

Military sources said the jets flew from Mactan Air Base in Cebu, central Philippines, and were on a reconnaissance mission in Basilan, the group's territory in Mindanao, southern Philippines.

Abu Sayyaf leader, Abu Sabaya, has been in constant dialogue with former Malaysian senator, Sairin Karno, and trader Yusuf Hamdam, for the release of the U.S. captives, sources told Gulf News.

Sabaya had requested earlier that President Gloria Arroyo appoint the two Malaysian nationals as negotiators. When she rejected this, the group executed U.S. captive, Guillermo Sobero, on June 12.

Sobero and the American couple were part of the 20 people abducted by the group from Dos Palmas Hotel in Palawan, south-western Philippines, on May 27.

The Abu Sayyaf is allegedly linked to the Al Qaida network of suspected terror mastermind, Osama bin Laden.