All the 21 American and Filipino hostages held by the Abu Sayyaf group have been sighted in a forested area on the southern island of Basilan, a military spokesman said.

"We have sightings of the remaining hostages. They (the Abu Sayyaf) have no liberty to move in the areas controlled by them because of the troops' presence and information provided by our DPAs (deep-penetration agents)," spokesman Lt. Col. Danilo Servando said. "Deep-penetration agents" is a term used to refer to government infiltrators in a rebel-held area.

At the same time, citizens have been providing tips about Abu Sayyaf infiltrators in their areas, said Colonel Damming Unga, of the anti-terrorist Task Force Mindanao. "We have been intensifying our efforts to arrest the terrorists, some of whom are believed to be hiding, or who have sought refuge with their relatives."

Lt. Col. Servando said the recently freed hostages had helped the military locate the Abu Sayyaf leaders. He added that based on the descriptions they were given, the hostages and the Abu Sayyaf leaders could be on one part of the mountains in the Sampinit complex.

At the same time, Lt. Col. Servando predicted that a major clash with the kidnappers was forthcoming. A total of 5,000 military men are posted in several parts of Basilan, but there has been a lull in the military assault following a cat and mouse game between the military and the Abu Sayyaf leaders.

The sighting of 21 hostages was confirmation that American hostage Guillermo Sobero, believed to have been beheaded by the Abu Sayyaf group last June 12, could still be alive.

The Abu Sayyaf group kidnapped 20 hostages, including Sobero and two American missionaries, Martin and Gracia Burnham, from Palawan, south-western Philippines, on May 27. The group took four more hostages when it landed in Lamitan, Basilan, on June 2; and 15 others during an attack on a coconut plantation in Lantawan, Basilan on June 11.

The group officially announced the beheading of four hostages, and the release of 14 others, leaving behind 21 more victims, including Sobero, in the custody of the group.