Western Mindanao Command (Westmincom) spokesman Maj. Eugene Batara said the one-hour firefight with the bandits led by Radullan Sahiron was so intense that it also left three Marines dead.
Troops led by the Marine Battalion Landing Team 9 (MBLT) managed to capture two rebels while chasing the main group led by Sahiron in Timpook, a forested mountain near Patikul.
The encounter came two days after Abu Sayyaf spokesman Abu Solaiman was killed by government troops in Bud Dajo, Talipao.
Solaiman, whose real name is Jainal Antel Sali Jr., was one of the three remaining ranking leaders of the Abu Sayyaf being hunted by the government.
Solaiman, who had a $5-million reward on his head from the US government, was killed last Tuesday, leaving Abu Sayyaf chieftain Khadaffy Janjalani and Sahiron on the most-wanted list.
The military is still trying to confirm if Janjalani is already dead through DNA tests on the body of a man exhumed in Jolo last month.
This leaves only Sahiron, whose forces are now being pursued by over 7,000 troops under "Oplan Ultimatum."
President Arroyo ordered the AFP to sustain the offensive against the Abu Sayyaf and capture the two Jemaah Islamiyah (JI) militants Dulmatin and Umar Patek who are both wanted for the 2002 Bali bombings.
Additional troops have been deployed in Sulu since Wednesday as the military intensified its offensive against the Abu Sayyaf.
Task Force Comet chief Brig. Gen. Ruben Rafael said troops have been mobilized to block possible escape routes in conflict areas.
On the other hand, troops were also ordered to be on alert for possible retaliatory attacks.
AFP Eastern Mindanao Command (Eastmincom) chief Lt. Gen. Rodolfo Obaniana said the troops were ordered to brace for attacks from the Abu Sayyaf.
"We are preparing for any eventuality or repercussion that would be brought by the death of Solaiman, which is considered to be a big blow to the Abu Sayyaf group," Obaniana said.
The Eastmincom held an emergency meeting along with Westmincom chief Lt. Gen. Eugenio Cedo and Autonomous Region in Muslim Mindanao (ARMM) Gov. Datu Zaldy Ampatuan to coordinate operations against the bandit group.
"One thing we are looking at is the possibility of retaliatory attacks by Abu Sayyaf following the death of Solaiman. We do not expect them to be sitting down and not doing anything about it. We have to be prepared," Obaniana stressed.
Cedo, for his part. said the military is expecting the bandits to regroup following the series of major encounters early this month that disrupted their terror plans and the escape of Dulmatin.
"They will now realize military forces will keep on catching them wherever they are. There is only one option for them to stay alive – that is if they want to surrender and live longer," Cedo said.
On Jan. 9, Binang Sali, spiritual adviser of the Abu Sayyaf, was killed in an encounter with Army Scout Rangers and intelligence operatives in Barangay Anuling in Patikul.
Three days earlier, government troops intercepted a pumpboat with several Abu Sayyaf, killing five of the bandits including middle-level leaders Abu Jubaida and Jundam Jumalul off the coast of Tawi-Tawi.
Also killed during the encounter was a certain Gufran, said to be a JI militant and close aide of Dulmatin.
Last Aug. 1, the military launched Oplan Ultimatum, aimed at neutralizing the Abu Sayyaf, which had given refuge to Patek and Dulmatin. -With James Mananghaya, Edith Regalado