Philippine commandos killed 11 Abu Sayyaf extremists on a remote southern island in a clash on Friday, an army spokesperson said.
Major Filemon Tan said dozens of Abu Sayyaf militants were also wounded in the 45-minute gun battle in the jungle of Jolo island. Abu Sayyag group is a small but brutal group known to be affiliated with Islamic State militants in Iraq and Syria.
"The mission is clear. Seek and destroy the Abu Sayyaf," Major Tan told Reuters.
"By all means, that's what we are doing and we will not stop until it's done," he added.
Major Tan also said 17 commandos were injured in the clash with about 100 Abu Sayyaf bandits.
The group is still holding about 20 hostages, including eight Indonesians, five Malaysians, a Norwegian and a Dutch national.
On Friday, the group beheaded one of its kidnap victims, Patrick Almodovar as his family failed to pay the ransom amount demanded by the militants, which had set the deadline for August 24, 2016.
Last April, the bandits killed a Canadian hostage, John Ridsdel, as the ransom deadline lapsed and later they executed another Canadian hostage, who was identified as Robert Hall.
The Abu Sayyaf group has become one of Asia's most lucrative kidnap rackets with the vast sums of ransom money.
The security experts say the militants are motivated less by Islamist ideology and more by the tens of millions of dollars from kidnappings.