13 Philippine marines killed in fighting with militants

American spy planes are helping Filipino troops quell a nearly three-week siege by Muslim militants in a southern city where 13 Philippine marines were killed in the biggest single-day loss for government forces, officials said Saturday.

A U.S. navy aircraft provided surveillance for the local troopsas the battle ragedFriday, confirming the involvementof the U.S. military in helping quell the urban insurrection at therequest of the Philippine government,Philippine military officialssaid.

An Associated Press journalist and photographer saw a U.S. navyP3 Orion plane hovering in cloudy skies aboveMarawion Friday. Theaircraft flew above rocket-firing Philippine helicopters that struckmilitant positions, causing plumes of smoke to billow skyward.

"We don't have adequate surveillance equipment, so we asked theU.S. military for assistance. It's non-combat assistance," militaryspokesman Brig. Gen.RestitutoPadillasaid by phone, citing aPhilippine government policy that bars foreign troops from localcombat.

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The U.S. Embassy in Manila said without elaborating that U.S.special operations forces were providing help to Filipino troopsbattling theMauteand AbuSayyafmilitants inMarawi.

"The United States is a proud ally of the Philippines, and wewill continue to work with the Philippines to address shared threatsto the peace and security of our countries, including oncounterterrorismissues," the embassy said in astatement.

Marines conducting house searches

Philippine marines were conducting a house-to-house search for militants allied with the Islamic State in Iraq and Syria who are still occupying parts ofMarawiwhen the battle erupted Friday, said Lt.-Col.Jo-arHerrera, spokesman for the Philippine army's 1st Infantry Division.

About 30 to 40 militants used civilians as human shields, making it hard for troops to operate, and also positioned themselves in the city's many mosques.

Forty other marines were wounded,Herrerasaid.

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Philippine military officials say the violence has left at least 138 militants and 58 government troops dead. At least 21 civilians have been killed, including a boy who was hit by suspected militant gunfire inside a Marawi mosque where his family had taken refuge, Padilla said.

Hundreds of thousands of people have fled the city, parts of which were reduced to rubble by fighting and government airstrikes in an attempt to dislodge the rebels.

"This temporary setback has not diminished our resolve a bit," said military spokesman Col. Edgard Arevalo. "It instead primed up our determination to continue our prudent advances to neutralize the enemy, save the innocent lives trapped in the fight, and set the conditions for the rehabilitation and reconstruction of Marawi."

Mom of 2 militant leaders captured

Filipino forces, meanwhile, captured on Friday the mother of two top militant leaders leading the siege.

Ominta Romato Maute, who is also known as Farhana, was arrested with two wounded men and several woman allegedly with assault rifles and other weapons in Masiu town in Lanao del Sur province.

Maute's husband, Cayamora, was arrested at a police checkpoint in the southern city of Davao on Tuesday. The two were detained on suspicion of providing financial and other support to their children who are involved in the fighting in Marawi, officials said.

Philippine President Rodrigo Duterte has declared martial law in the Mindanao region, the southern third of the Philippines and home to a decades-long Muslim separatist rebellion.

Defence Secretary Delfin Lorenzana, the designated administrator of martial law, has ordered the arrest of nearly 200 militants, politicians and other suspected civilian backers of the unprecedented uprising in Marawi, the mosque-studded heartland of Islamic faith in the south of the predominantly Roman Catholic nation.

The Marawi siege followed a May 23 army raid that failed to capture a top terror suspect, Isnilon Hapilon, who has been
designated by the Islamic State group as its leader in Southeast Asia. The raid, however pre-empted a plot by hundreds of militants waving ISIS-style black flags to capture Marawi and kill Christians, military officials say.