Manila: The leader of a key Filipino-Muslim rebel group died after suffering a stroke on Tuesday morning in the country’s south, sources said.

Ameril Umbra Kato, leader of the seven-year old Bangsamoro Islamic Freedom Movement (BIFM), a splinter group of the 37-year-old Moro Islamic Liberation Front (MILF), died of cardiac arrest in his hideout in Bagan village, Guindulungan town, Maguindanao, at two on Tuesday morning, said Mohagher Iqbal, a MILF peace negotiator.

MILF, the group that Kato broke away from, signed a pro-autonomy peace settlement with the Philippine government in 2014.

Kato was buried in Kateman village, Guindulungan town before eight on Tuesday morning, Iqbal said, adding he received the news from a reliable source.

Members of BIFM and its armed wing, the Bangasmoro Islamic Freedom Fighters (BIFF), confirmed Kato’s death, mayor Samsodin Dimaukom of Datu Saudi Ampatuan in Maguindanao said.

Armed Forces Chief of Staff Gen Gregorio Catapang ordered Brig. Gen. Arnold Quiapo, head of the Intelligence Service of the Armed Forces of the Philippines (ISAFP) to confirm Kato’s death.

In November 2011, Kato suffered a stroke but had recovered.

The first stroke had come just a month after the MILF expelled him as commander of its 105th command in October 2011. Since then, he and his men relentlessly attacked MILF’s 105th base command.

In 2008, Kato faced charges for leading 500 former MILF members in attacking civilian communities in the south — after the Supreme Court said in a ruling that the pro-autonomy peace settlement of the Philippine government and the MILF entitled Memorandum of Agreement on Ancestral Domain was unconstitutional. It happened during the time of former President Gloria Arroyo.

Kato openly criticised the peace talks then, saying the Philippine government and the MILF would never reach a political settlement. He was later proved wrong as the two parties forged a pro-autonomy peace settlement for enhanced self-rule for Filipino Muslims in the south, in 2014.

But on January 25 a government special police unit clashed with militants from the MILF, the BIFF and two other groups in a fatal mis-encounter after an anti-terror operation that killed Malaysian bomb maker expert Zulkifli Bin Abdhir in a village in Mamasapano town, Maguindanao.

The incident left 44 policemen, 18 MILF rebels, and five civilians dead.

The incident prevented lawmakers from reviewing a proposed bill that would enforce the Philippine government-MILF political settlement. Peace talks between the Philippine government and the MILF began in 1997, with Malaysia, a member of the Organisation of Islamic Cooperation, as peace broker.