At least 35 people have been injured after two bombs exploded at an amateur boxing match in the Philippines during an annual Roman Catholic holiday festival.

Police recovered an 81mm mortar cartridge and a mobile phone apparently used to detonate the homemade bombs in the town of Hilongos in Leyte province on Wednesday, a police spokeswoman said.

Senior inspector Jenyzen Enciso said no suspects had been identified and no group had claimed responsibility.

Hilongos Mayor Alberto Villahermosa told CNN Philippines at least 35 residents were injured in the twin blasts.

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Most of the victims were injured beneath their knees after an improvised explosive device (IED) was detonated at the boxing match at the Plaza Rizal.

A second explosion followed the first blast, which Mr Villahermosa said was weaker because the IED wasn’t properly assembled.

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The attack follows a Christmas Eve grenade explosion outside a Catholic church on the southern island of Mindanao, which wounded 16 people.

Police said there was no indication the two attacks were linked.

Filipino forces have been placed on alert amid sporadic offensives in the south against Muslim militants, including Abu Sayyaf gunmen and armed sympathisers of Isis who have targeted the capital Manila, and other urban centres in the past.

President Rodrigo Duterte has warned of the threat of a proliferation of festering Islamist militancy in the Philippines and an infiltration by Isis if offensives to drive its fighters out of Iraq and Syria succeed.

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Communist guerrillas also have a presence in Leyte province, about 380 miles south east of Manila, but there was no immediate indication they or Muslim militants were involved.