MANILA – President Rodrigo Duterte on Thursday said the crisis unfolding in Mindanao was “purely” the plan of the Islamic State, as he warned of dire consequences if the problem was not addressed decisively.

In a speech in Malacañang, Duterte said he knew that the ISIS was up to something when top Abu Sayyaf leader Isnilon Hapilon, known as the international terror group's point man in Southeast Asia, left his lair in Mindanao's deep south for the region’s mainland.

“Iyung rebellion sa Mindanao, it’s not Maute, it’s purely ISIS with a different branch,” Duterte said.

“Itong Marawi [siege] has long been planned. It could not be just a decision na ‘let’s go to Mindanao.’ Nung si Hapilon na ang pinadala sa central Mindanao and he was the anointed emir [of ISIS], doon na ako nakaamoy na something terribly wrong is going to happen kasi dala-dala na niya ang ISIS,” said the President.

ISIS is known to be behind bloody attacks in key cities around the world, including bombings in Europe.

The recent discovery that foreign jihadis were fighting alongside domestic terror groups in Marawi seemed to lend credence to long-running reports that the Islamic State was trying to establish a foothold in Asia through the Philippines as it dealt with losses in Iraq and Syria.

In a press briefing in Malacañang, Defense Secretary Delfin Lorenzana said there were indications that the eight foreign fighters so far killed in the ongoing clashes were ISIS militants.

Lorenzana said the military has so far identified 2 Malaysians, 2 Saudis, 2 Indonesians, a Yemeni, and a Chechen as among those killed in the siege, which started on May 23.

“The report we got from the civilians from Marawi is they saw a lot of foreign-looking fighters,” the defense chief said.

“There could be more that we killed that we have not identified," he added.

Lorenzana said about 50 to 100 militants remained holed up in Marawi City, and that efforts were now underway to flush them out, with the Philippine Marines sending a battalion to neutralize continuing resistance in the city.

“Some of them have already started to rejoin their barangays. [They are] going to their former places,” he said of the militants.

President Rodrigo Duterte on May 23 placed Mindanao under martial following the clashes, which have so far left 164 dead.

Among the fatalities were 120 terrorists, 25 government troops and 19 civilians, Armed Forces of the Philippines spokesperson Col. Edgard Arevalo told DZMM.

Violence erupted in the city after government troops attempted to arrest Hapilon. He managed to evade arrest but Lorenzana said Hapilon remains in Marawi City.