At least 17 people are dead after a military plane which was transporting troops missed a runway and crashed in the Philippines, the nation's defence secretary said.
Delfin Lorenzana said around 40 others were rescued from the burning wreckage of the C-130 aircraft in Bangkal village in the mountainous town of Patikul in southern Sulu province.
He said the Philippine air force plane had 92 people on board, including three pilots and five crew. The rest were army personnel.
Government forces have been battling Abu Sayyaf militants in predominantly Muslim Sulu province for decades.
The cause of the crash was not immediately clear but it is thought to have been due to an attack, an army spokesman said.
Chief of Staff General Cirilito Sobejana said the aircraft was transporting troops from southern Cagayan de Oro city.
"It's very unfortunate," Gen Sobejana told reporters. "The plane missed the runway and it was trying to regain power but failed and crashed."
The airport in Sulu's main town of Jolo is located a few miles from a mountainous area where troops have been battling Abu Sayyaf. Some militants have aligned themselves with the Islamic State group.
The United States and the Philippines have separately blacklisted Abu Sayyaf as a terrorist organisation for bombings, ransom kidnappings and beheadings. It has been considerably weakened by years of government offensives but remains a threat.