At least nine fighters of the Abu Sayyaf group and a soldier have been killed following heavy fighting between the armed group and government forces in southern Philippines.
The fighting on Thursday in the jungles of Patikul in Sulu Province also left at least 19 armed fighters and six government personnel wounded, according to Major Filemon Tan, a military spokesman.
Tan said that the fighting began when troops encountered suspected members of the armed group during an operation to track down hostages being held by the group in Sulu.
Abu Sayyaf group beheads second Canadian hostage
Clashes have also been going on in the neighbouring island of Basilan, where an estimated 200 Abu Sayyaf fighters carried out attacks on a military headquarters, according to local news reports.
It was not clear if there were casualties from that fighting. But many residents have been forced to flee.
The Abu Sayyaf are holding captive a Norwegian, seven Indonesian sailors and other Filipinos.
They have threatened to execute Norwegian Kjartan Sekkingstad if a ransom is not paid for him.
Sekkingstad was abducted with two Canadians and a Filipino woman in September from the southern island of Samal.
Following the swearing in of President Rodrigo Duterte on June 30, the Philippines' new military chief warned of a "shock and awe" offensive to wipe out the armed group, which has pledged allegiance to the Islamic State of Iraq and the Levant group (ISIL, also known as ISIS).
Earlier in June, the group claimed they had beheaded Robert Hall, a second Canadian man who had been held captive since September 2015. Another Canadian hostage was beheaded in April, after a ransom was not paid.
On June 24, the Abu Sayyaf freed Filipino Marites Flor.
The group initially demanded a ransom of $21.7m for each captive, but they lowered the amount to $4.2m for each before Hall was killed on June 13.
The United States and the Philippines have blacklisted the Abu Sayyaf as a terrorist organisation.
Source: Al Jazeera and agencies