The US embassy in Manila and the Philippine military were quoted by the Reuters news agency Saturday as saying that US special operations forces were "assisting" in Marawi where 200,000 residents have been displaced by urban battles.

Philippine military spokesman Lieutenant Colonel Jo-Ar Herrera said US personnel were "just providing technical support" and not fighting. That followed sightings on Friday of a US P3 Orion surveillance aircraft over Marawi.

In a televised press conference earlier on Saturday, Herrera said that 13 Philippine marines had been killed in battles with some 200 insurgents allied to the "Islamic State" (IS) militant group.

There were "strong indications," he added, that two militant leaders might also have been killed.

House-to-house

On Friday, airstrikes by the Philippine military targeted buildings in three districts of Marawi, where the insurgents were reportedly holding around 100 hostages, including a Catholic priest.

Military casualties stemmed from intense, house-to-house fighting and the militant's use of improvised explosive devices, Herrera added.

The marines' deaths added to an overall two-week death tollput at 204. The army listed 21 civilians, 138 militants and 45 police and soldiers killed.

Police said one of the latest fatalities was a 15-year-old boy killed by a stray bullet attributed to a militant sniper while praying inside a mosque. 

The Agence France-Presse news agency reported the military as saying that the militants occupied about 10 percent of the city and were using bomb-proof tunnels and anti-tank weapons.

Turn in relations?

US military involvement on the island of Mindanao, 800 kilometers (497 miles) south of Manila, would mark a turn in strains exemplified by President Rodrigo Duterte's past pledges to expel US troops after decades of cooperation.

Washington deployed special forces soldiers to Mindanao in 2002 to train and advise Philippine units then fighting Abu Sayyaf militants. Although the US has no permanent presence in the country, Washington has maintained 50 to 100 soldiers in the south of the country on rotational drills.

ipj/jlw (Reuters, dpa, AFP)