US confirms it is ‘assisting’ Philippine army in besieged Marawi where fighting broke out more than two weeks ago.

At least 13 Philippine marines were killed on Friday as the battle against fighters linked to the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) continued in the besieged southern city of Marawi.

The death toll was provided by the Philippine army on Saturday, which also said that at least 40 others were wounded in a 16-hour fight against members of the Maute group.

“There was an intense, house-to-house firefight between the marines and the local terrorist group”, Jo-Ar Herrera, army spokesman, told a televised press conference.

He said the marines, who were taking part in an operation to rescue about 100 people who are being held hostage by Maute, were killed by improvised explosive devices set off by the group’s fighters.

The setback for the Philippine military comes more than two weeks after the start of the deadly siege of Marawi City, which prompted Philippine President Rodrigo Duterte to declare martial law on May 24 on the southern island of Mindanao

Officials said an estimated 500 to 1,000 civilians are trapped in the built-up area occupied by the fighters, which also came under heavy aerial bombardment on Friday.

At least 200 people, including soldiers, armed gunmen and civilians have been killed and more than 200,000 people have been displaced.

Duterte declared martial law on the island of Mindanao on May 24 [Romeo Ranoco/Reuters]

US support

As the fighting intensifies, the United States said on Saturday that its special forces were providing technical support to the Philippine military in Marawi City.

“US special operations forces are assisting” the armed forces of the Philippines in Marawi “at the request of the government of the Philippines”, an unnamed US official told Reuters news agency.

The official gave no details of the US involvement, but a US surveillance plane was seen flying over Marawi on Friday. There is no evidence Washington has put troops on the ground there.

The assistance comes after months of strain between the two long-time allies that was stoked by Duterte’s pledges to throw US troops out of the country.

Al Jazeera’s Jamela Alindogan, reporting from the Philippine capital of Manila, said that despite Duterte’s hostile declarations, the US military’s assistance “comes as no surprise because … American forces have always been present – although they are there primarily for technical and intelligence support”.

READ MORE – The battle for Marawi: Confusion and contradictions

Washington deployed special forces soldiers to Mindanao in 2002 to train and advise Philippine units fighting the Abu Sayyaf group in an operation that once involved 1,200 Americans. It was discontinued in 2015 but a small presence remained for logistics and technical support.

The US and the Philippines have been allies for decades. Their relationship provided Washington with a strategic foothold in Asia and offered Manila a shield against China’s assertiveness in the region.

But Duterte has openly scorned the alliance, seeing it as an obstacle to a rapprochement with China, and has repeatedly lambasted Washington.

The Philippine military has said its aim is to end the siege in Marawi by Monday [Reuters]

Maute matriarch arrested

On Friday, police also arrested the mother of the Maute brothers, the two men leading the fighters in Marawi City.

Ominta “Farhana” Maute, the mother of Abdullah and Omar, was detained with nine other people, including two wounded men, in the town of Masiu.

“Farhana was said to be buying vehicles and firearms for their escape outside Lanao del Sur province,” said Chief Superintendent Theodore Sindac, a regional police director.

“Several high-powered firearms and improvised explosive devices were confiscated from their possession,” Sindac added.

The Maute brothers’ father was arrested on Tuesday and transferred to a Manila detention facility amid fears the group’s fighters might attempt to rescue him.

Both Maute and Abu Sayyaf have declared their allegiance to ISIL.

Maute wants to set up an Islamic state in Lanao province in Mindanao’s north, one of the poorest regions in the Philippines.

‘Take down fake Facebook accounts’

Also on Friday, the Philippine military asked Facebook to close dozens of accounts linked to fighters in Marawi City.

The military’s Herrera said the armed forces’ social media unit had uncovered 63 accounts belonging to the fighters and their supporters.

“These 63 accounts are spreading malicious information and misinformation that affect the information landscape and the mindset of every Filipino,” Herrera told reporters.

The military has asked Facebook Philippines “to conduct necessary measures to take down these fake accounts”, Herrera added.

OPINION – Mindanao crisis: A city on fire

When asked about the military’s request, Facebook told the AFP new agency that it would remove accounts that promoted “terrorism”.

“We want to provide a service where people feel safe. That’s why we have community standards that explain what you can and cannot do on our service,” a Facebook statement said.

“Our community standards do not allow groups or people that engage in terrorist activity, or posts that express support for terrorism. Fake accounts are also prohibited.”

‘Don’t kill us’: Fleeing civilians recall Marawi ordeal

The military said on Friday its aim was to end the siege in Marawi City by Monday, the Philippines’ independence day.

“The chief of staff made an announcement, hoping that by Monday we can freely wave our flags in every corner of Maraqi and we are working feverishly to do that,” military spokesman Restituto Padilla told reporters.

Also on Friday, the president’s office issued a statement saying the traditional celebrations to commemorate independence day had been cancelled by Duterte as he wanted to focus on the crisis in Marawi.