In addition to crimes in the Philippines, // Hapilon has a $5 million dollar reward on his head // from the US FBI for hostage taking.

MANILA: Philippine soldiers killed 15 militants // and seriously wounded their leader, // believed to be the Islamic State's representative in the country, // following air and artillery strikes in a southern province, // a senior military official said on Sunday.

Isnilon Hapilon, also known as Abu Abdullah // and a leader of the Philippine militant group Abu Sayyaf, //  might die  // as he needed immediate medical treatment, // military chief General Eduardo Ano told reporters, // citing intelligence and communications intercepts.

"He needs blood transfusion. // Without proper medical treatment, // he may die," Ano said.

Philippine forces on Thursday // dropped bombs and fired shells // at rebel positions in the mountains of Lanao del Sur // in a bid to flush out Hapilon. // The province is a stronghold of the Maute rebel group, // which has also pledged allegiance to Islamic State.

Hapilon is // on the Federal Bureau of Investigation's most wanted list // for his role // in the kidnapping of 17 Filipinos and three Americans in 2001 //  and carries a bounty of US$5 million.

One of those killed is an Indonesian // but Ano said // they were still "digging and doing more investigation" // about the foreigner's background. // Hapilon was with two other foreigners // whose nationality was uncertain, // he said.

President Rodrigo Duterte // appealed on Friday to the country's Muslim separatist groups // to deny sanctuary to militants // with links to Islamic State, // warning a war would ensue // that would put civilians in danger.

A day before he made the appeal, // the defence minister said //  foreign intelligence reports showed // Hapilon was getting instructions from Islamic State // to expand in the Philippines, // in the strongest sign yet // of links to the Middle Eastern militants.

Duterte has said // he could no longer contain the extremist "contamination" // and urged two Muslim separatist rebels groups -//  the Moro Islamic Liberation Front and the Moro National Liberation Front - // to rebuff Islamic State's advances.

Ano said // a firefight could be expected // between soldiers and Hapilon's group // following the strikes.