GENEVA (Reuters) - A Muslim indigenous community on the Philippine island of Mindanao has suffered widespread human right abuses that could intensify with President Rodrigo Duterte's extension of martial law there, U.N.-appointed experts said.
Duterte has called the island a "flashpoint for trouble" and for atrocities by Islamist and communist rebels.
Lawmakers this month overwhelmingly backed his plan to extend martial law there through 2018, which would be the country's longest period of such emergency rule since the 1970s era of strongman Ferdinand Marcos.
The militarisation has displaced thousands of the Lumad people and some have been killed, said Victoria Tauli-Corpuz and Cecilia Jimenez-Damary, the U.N. Human Rights Council's special rapporteurs on the rights of indigenous peoples and internally displaced people.
"They are suffering massive abuses of their human rights, some of which are potentially irreversible," the pair said in a statement late on Wednesday.
"We fear the situation could deteriorate further if the extension of martial law until the end of 2018 results in even greater militarisation."
The Philippines was obliged by international law to protect indigenous peoples and ensure human rights abuses were halted and prosecuted. "This includes killings and attacks allegedly carried out by members of the armed forces," they said.
The government fears that mountainous, jungle-clad Mindanao, a region the size of South Korea that is home to the Lumad, could attract foreign militants.
The U.N. experts said they had information suggesting that 2,500 Lumads had been displaced since October, and that Lumad farmers had been killed by military forces on Dec. 3 in Barangay Ned in the province of South Cotabao.
"We fear that some of these attacks are based on unfounded suspicions that Lumads are involved with militant groups or in view of their resistance to mining activities on their ancestral lands,” the pair said, without giving further details.
A spokesman for Duterte said the martial law extension was needed "to quell the remaining terrorists who brought destruction to Marawi and its neighbouring communities".
Its legal and factual basis had been "clearly established based on the security assessment by our ground commanders", Harry Roque added in a statement.
Since Duterte took power in June last year, the Philippines has also drawn international criticism for the killing of about 3,900 people in police anti-drugs operations. Police deny allegations by human rights advocates that many of the killings were executions.
(Reporting by Tom Miles; additional reporting by Enrico Dela Cruz in Manila; editing by John Stonestreet)