Thousands of civilians have fled their homes in the southern Philippine island of Jolo after deadly clashes between troops and militants, officials say.
About half of those killed on Thursday were soldiers
More than 50 people were killed on Thursday, almost half of them soldiers.
Reinforcements have begun to arrive in Jolo, as the military steps up its campaign against Islamist rebels.
Troops backed by US military trainers have been fighting militants affiliated to various groups, hiding in the island's mountainous terrain.
Thursday's fighting began when a troop convoy was ambushed near the town of Maimburg, leaving 10 soldiers dead.
Fifteen more soldiers were killed and 17 were wounded in gun battles after reinforcements were flown in to engage with militants.
The Moro National Liberation Front (MNLF) - which signed a peace deal with the government in 1996 - claimed responsibility for the ambush, saying it was in retaliation for earlier army offensives.
But military officials have also blamed Abu Sayyaf, the group behind the Philippines' worst terror attack - a ferry bombing in 2004 that killed more than 100 people.
On Saturday local officials appealed for food, water and medicines as people flocked to community centres and schools, fearing more fighting.
Another 1,000 soldiers are being sent to Jolo, to join 4,000 already stationed there.
"We are continuing with our operation to be able to cordon off and finally destroy the Abu Sayyaf," army spokesman Ernesto Torres said.
The stakes were raised last month after 14 marines were killed on nearby Basilan island, with 10 of them beheaded.
The skirmishes began in Jolo, some 950km (600 miles) south of the capital, Manila, on Tuesday.
The US has listed Abu Sayyaf as a terrorist organisation and says it has links to Al-Qaeda, as well as the regional militant group Jemaah Islamiah.