U.S. reconnaissance aircraft scoured Abu Sayyaf territory and passed on information to the ground, but Filipino troops could not track the rebels or their hostages.

P3 Orion aircraft pin-pointed areas which could be infested with rebels. "They spotted areas for us to check, but ground troops yielded negative information," said Maj. Gen. Glicerio Sua, an Army division commander.

Ground troops also identified area for surveillance at night, but American aircraft drew a blank. Maj. Gen. Sua, hinted at a frustrating effort to catch Abu Sayyaf rebels. P3 Orion aircraft have flown two sorties over Basilan, he added.

Earlier, critics said the U.S. unilaterally did a surveillance mission over Philippine skies. National Security Council head Roilo Golez added that the U.S. can call for an air strike in case an Abu Sayyaf hideout is spotted.

American and Philippine governments have been sharing information even before the terror attacks in the U.S., sources said.

The military said only 60 to 70 Abu Sayyaf members are actively operating in Jolo, Basilan Island, and Tawi-Tawi. The U.S. and the Philippine governments believe that the Abu Sayyaf Group has links to the Al Qaida network.

Adds Our Manila Bureau Chief: Meanwhile, the Philippine Cong-ress has created a committee to monitor the implementation of the Philippine-U.S. Visiting Forces Agreement (VFA), the basis of the six-month long war games in Mindanao.

Senator Blas Ople, chairman of the senate committee on foreign relations, and Senator Ramon Magsaysay Jr., chairman of the senate committee on national defence and security, will represent the upper house in the committee.

Congressman Prospero Pichay and Apolinario Lozada Jr. will act as co-chair of the committee.

The committee aims to accommodate all the complaints of those affected by the war games.

An eight-man team of U.S. Army aviation officials arrived in central Philippines to investigate the crash of an MH-47E Chinook helicopter off Negros Oriental last Friday, killing all 10 crew, said U.S. military spokesperson Major Cynthia Teramae.

The team will conduct interviews, review flight data logs and inspect debris recovered from the crash site. "The investigation will continue for an indefinite period of time until the team determines the cause of the accident," Teramae said.

The investigating team is composed of a senior major, four senior warrant officers, two senior non-commissioned officers and one captain. They came from the U.S. Air Force Special Operations Command Head-quarters in Florida; Fort Rucker in Alabama and Seoul, South Korea.

Two HH-60G Pave Hawk helicopters were sent to central Philippines from Kadena Air Base in Japan to help search for the bodies of the missing U.S. soldiers, Teramae said.

The rescue operation will proceed. The Pave Hawks belong to the U.S. Air Force 33rd Rescue Squadron based in Okinawa. Rescuers managed to recover only three bodies last week.

Two Black Hawk choppers arrived in Zamboanga City late on Tuesday to participate in the war games, said Joint Task Force commander Brig. Gen. Donald Wurster.

Three hundred U.S. troops are now in Zamboanga City, some in Cebu, central Philippines, and 160 in Basilan island, where Abu Sayyaf rebels are holding U.S. missionary couple Martin and Gracia Burnham.