Philippine troops have killed another senior leader of the brutal Abu Sayyaf group responsible for kidnapping Malaysians and Indonesians in the waters off Sabah, including an engineer who was beheaded in 2015.
Military chief Eduardo Ano said in a statement that Alhabsy Misaya was killed in a clash with marines late on Friday in the jungles between the towns of Indanan and Parang, in Sulu province - an Abu Sayyaf stronghold 950km south-west of Manila.
Misaya was "considered to be one of the most notorious kidnappers in southern Philippines", said General Ano.
His group was behind the abduction in May 2015 of two Malaysians - restaurant manager Thien Nyuk Fun, 50, and engineer Bernard Then, 39 - in Sandakan town in Sabah.
Ms Thien was released in November 2015, after her family paid some 30 million pesos (S$835,000) in ransom.
However, Mr Then was beheaded more than a week after Ms Thien's release, purportedly because the ransom offered for his release was not enough.
Misaya and two other Abu Sayyaf leaders were also allegedly behind the abduction of Chinese national Gao Huayun and Filipino resort worker Marcy Dayawan in April 2014.
Ms Gao and Ms Dayawan were taken from the Singamata Adventures and Reef Resort in Semporna town in Sabah.
They were released two months later, after Ms Gao's family reportedly paid a ransom of about 300 million pesos.
Last year, Misaya's group seized 10 Indonesian and five Malaysian tugboat crewmen.
All have been released, after ransom was paid.
Gen Ano also blamed Misaya for at least three bomb attacks, including one in 2002 that killed United States serviceman Mark Jackson.
Misaya's death comes just days after Philippine security forces killed Abu Sayyaf spokesman Muamar Askali, alias Abu Rami.
Askali, who was killed on April 11, was described as a "rising star" in extremist circles and was blamed for several high-profile kidnappings.
He was leading a band that sailed north for nearly 800km from an Abu Sayyaf base in Indanan town in Sulu to Bohol province in central Philippines to abduct tourists.
Eight of the 10 militants who were with him were also killed.
Among the dead was the Abu Sayyaf point man in central Philippines, Joselito Milloria.
Last week, security officials reported that three Indonesians and one Malaysian were among 37 Islamic militants killed in clashes in the war-torn southern Philippines.
The Abu Sayyaf group has capitalised on decades of instability in the region and generated tens of millions of dollars from piracy and ransom payments, using the funds to purchase arms, high-powered boats and modern navigation equipment.
Last month, the terrorist group beheaded Mr Jurgen Kantner, an elderly German sailor, after a deadline for a US$600,000 (S$838,000) ransom passed.
The Philippine military says the militants are still holding at least 24 more hostages - 13 Vietnamese, seven Filipinos, a Dutch, a Japanese and two Indonesians.