The Philippine military on Monday said it was close to retaking a southern city held for a seventh day by militants, as helicopters unleashed more rockets on positions held by the rebels aligned with Daesh.
The clashes in Marawi city with the Maute militia, a group hardly known a year ago, has become the biggest security challenge of Rodrigo Duterte's 11-month presidency, with gunmen resisting air and ground assaults and still in control of central parts of a city of 200,000 people.
The military said the rebels may be getting help from "sympathetic elements" and fighters they had freed from jail during the rampage that started on Tuesday and caught the military by surprise.
"Our ground commanders have assured that the end is almost there," military spokesperson, Restituto Padilla told reporters.
"We can control who comes in and who comes out, who moves around and who doesn't. And we're trying to isolate all these pockets of resistance."
More than 100 people have been killed, most of them militants, according to the military, and most of the city's residents have fled.
The military said the Maute group was still present in nine of the city's 96 Barangays, or communities.
The Maute group's ability to fight off the military for so long will add to fears that Daesh's radical ideology is spreading in the southern Philippines and it could become a haven for militants from Indonesia, Malaysia and beyond.
The government believes the Maute carried out their assault before the Muslim holy month of Ramadan to capture the attention of Daesh and earn recognition as a Southeast Asian affiliate. Marawi city is on Mindanao, home to many Muslims in the predominantly-Catholic Philippines.
Iligan City, 38 kilometres (24 miles) away, was overflowing with evacuees and was on lockdown over fears that fighters had sneaked out of Marawi by blending in with civilians.
"We don't want what's happening in Marawi to spill over in Iligan," said Colonel Alex Aduca, chief of the Fourth Mechanized Infantry Battalion.
The seige of Marawi started when Maute rebels went on the rampage after a military operation that failed to arrest Isnilon Hapilon, who the government believes is a point man for Daesh in the Philippines.
Some troops tried to eliminate Maute snipers on Monday as others guarded deserted streets, taken back block-by-block.
Helicopters circled the lakeside city and smoke poured out of some buildings. Artillery explosions echoed.
Though most people have left, thousands are stranded, worried they could be intercepted by militants at checkpoints on routes out of the city.
There were still bodies of civilians in Marawi and residents urged the military to halt air strikes, said Zia Alonto Adiong, a politician involved in evacuation efforts.
"The anticipation of death is worse than death itself," he told news channel ANC. "We appeal to our military forces to do a different approach."
The military said air strikes were taken on "known and verified enemy positions."
"We are using precision ammunition in our surgical air strikes," said another army spokesman, Colonal Edgard Arevalo. "We have highly skilled and trained pilots delivering the payload."
Bodies of what appeared to be executed civilians were found in a ravine outside Marawi on Sunday as the crisis took a more sinister turn. Most of the eight men were shot in the head and some had bound hands.
Duterte imposed martial law last week on Mindanao, an island of 22 million people where both Marawi and Iligan are located, to quell the unrest and wipe out militancy.
Duterte calls for united opposition to Daesh
The Philippine president made an unconventional offer on Saturday to Muslim separatists and communist rebels to join his fight against extremists, and said he would give them the same pay and benefits as government troops.
Rebel groups on Monday said they opposed Daesh-linked militants in the Philippines, but gave no indication they would take up Duterte's offer to fight alongside government troops.
"All terror groups are opposed by the Communist Party of the Philippines (CPP)-New People's Army (NPA)," Luis Jalandoni, the Maoist-led rebel group's chief peace negotiator, told domestic broadcaster ANC from the Netherlands.
"In that sense, the CPP and NPA would be together with the Duterte government in opposing the Maute group and the Abu Sayyaf."
He did not say whether the rebel group would take up the president's offer to give guerrillas the same pay and benefits as government troops and build houses for them, if they joined the battle to defeat a common enemy.
Duterte said southern separatists and communists knew the local terrain and had fighting experience.
"You already know how to use a gun. Just practise pulling the trigger," he said.
Ghadzali Jaafar, a senior leader of the separatist Moro Islamic Liberation Front (MILF), told Reuters its central committee would need to meet to discuss the president's offer, but was against Islamist extremism.
The MILF, which signed a peace deal with the government in 2014 but has yet to fully implement it, said last week it would cooperate with the government and help people affected by the Marawi unrest.
"We call on our forces to extend all necessary assistance to the people of Marawi to ensure their safety and frustrate the aim of any group or groups to sow divides in our communities," it said in a statement.
The Moro National Liberation Front appeared to be the only rebel group ready to join the government. Its leader and founder leader, Nur Misuari, suggested the idea to Duterte and volunteered his men to join the battle in Marawi.