The killing of Commander Modasir brought to 13 the number of Abu Sayyaf leaders who have been "neutralized"  either killed in battle or who have surrendered  since the military’s Task Force Trident launched an all-out offensive against the extremist group last Sept. 16.
Maj. Gen. Narciso Abaya, chief of Task Force Trident and the Army’s Western Mindanao Command, said elements of the 77th Infantry Battalion were on combat patrol when they caught up with Modasir and his 20 fully armed followers in Barangay Lati, Patikul town.
Two hours earlier, troops of the 55th Infantry Battalion clashed with 30 followers of Abu Sayyaf leader Ghalib Andang alias Commander Robot in Talipao town.
The military said many guerrillas were killed or wounded in these skirmishes.
Authorities believe that Andang and fellow Abu Sayyaf leader Mujib Susukan have placed their men on the defensive to slow down military men pursuing them.
The military is on its third month of pursuing the extremist rebels to rescue American Jeffrey Schilling and Filipino dive master Roland Ullah.
Ullah is the last of the Sipadan hostages still being held captive by the rebel-bandits who reportedly amassed more than P245 million in ransom money in exchange for the release of their European and Malaysian captives.
Earlier, authorities claimed to have received reports that Ullah might have joined his captors who have subjected him to indoctrination.
In another development, Moro Islamic Liberation Front (MILF) guerrillas fired anti-tank rockets at a military convoy near the Maguindanao town of Talayan last Thursday night, wounding an Army captain, a lieutenant and three infantrymen, according to Col. Hilario Atendido.