United States special forces are helping Philippine troops retake the southern city of Marawi from hundreds of ultra-radical Muslims who have managed to hold back an entire army brigade for over two weeks.
Security officials confirmed for the first time the presence of the American forces yesterday as they told reporters that two of the militants' leaders had likely been killed. They also announced that 13 more Filipino marines died in an ambush last Friday.
Lieutenant-Colonel Jo-Ar Herrera, spokesman for the Task Force Marawi, said the Americans were providing only "technical support" in the battle and were not involved in the physical fight.
"Their participation is limited to intelligence sharing," he said.
The US Embassy in Manila said in a statement that US special forces were helping at the request of the Philippine government, but added that it could not disclose "operational details".
A P-3 Orion surveillance plane was seen flying over Marawi last Friday, said local media reports.
The US has had a logistical military presence in the Philippines that once involved 1,200 Americans.
But a programme to advise the Philippine army on fighting militant groups in the war-torn southern island group of Mindanao was discontinued in 2015.
Ties between the US and the Philippines have been strained since President Rodrigo Duterte took office in June last year.
Mr Duterte has chafed at US criticism of his narcotics war, which has led to thousands of extrajudicial killings of drug users and other criminals both by police and vigilantes.
He has threatened to boot out all US forces in the Philippines, saying their presence was creating tensions with China.
But he had what the White House described as a "very friendly" phone call with US President Donald Trump in April, and has since said his differences with the US were with former president Barack Obama's administration.
Philippine security forces have struggled to dislodge hundreds of Muslim extremists, from the Maute and Abu Sayyaf groups, who seized large parts of Marawi on May 23, after a botched raid on the hideout of Isnilon Hapilon, designated by the Islamic State in Iraq and Syria as the head of its South-east Asia wing.
While the military now controls most of Marawi, some 100 gunmen are still holed up in a corner of the city where they have been using buildings and mosques as bunkers.
They have been rolling back army assaults with anti-tank weapons and sniper fire, and by using civilians as human shields. They move around using bomb-proof tunnels.
Officials say that foreign nationals are among the militants in Marawi, with the list of countries and territories including Saudi Arabia, Indonesia, Malaysia, Yemen, India and Chechnya.
An early morning push by a group of marines into one of the militants' remaining strongholds ended in disaster last Friday. Thirteen marines, including an officer, were killed when they ran into dozens of gunmen who rained rocket-propelled grenades on them and set off improvised explosive devices.
The latest casualties bring the number of Philippine troops killed in the fighting to 58.
At least 20 civilians and around 138 terrorists have also died.
Lt-Col Herrera said yesterday there were "strong indications" that two leaders of the Marawi attacks - brothers Omarkhayam and Madie Maute, have died in an air strike. A third brother, Abdullah, is believed to be still fighting with his men in Marawi.
Brigadier-General Restituto Padilla, the military spokesman, said last Friday that the Philippine flag would be flying all over Marawi by tomorrow, the Philippine independence day.
SEE TOP OF THE NEWS