By Ian Nicolas P. Cigaral

PRESIDENT Rodrigo R. Duterte plans to extend military rule in Mindanao until the end of the year to defeat a band of Islamic State (IS)-inspired militants that overran Marawi City and to support the rehabilitation of the southern city.

President Rodrigo Duterte salutes in front of the flag-draped casket containing one of the slain marines shortly after the bodies of slain marines arrived from Marawi at a military base in Manila on June 11, 2017. AFP

Clashes between government forces and pro-IS Maute terrorist group broke out in Marawi on May 23 — triggering the biggest internal security crisis in the Philippines since the 2013 siege of Zamboanga City by the Moro National Liberation Front (MNLF).

Mr. Duterte, in his Proclamation 216 issued on May 23, declared martial law and enforced warrantless arrests over Mindanao.

In a seven-page letter to congressional leaders, Mr. Duterte said: “Because public safety requires it, I call upon the Congress to extend until 31st December 2017 or for such a period of time as the Congress may determine the proclamation of martial law.”

“I have come to the conclusion that the existing rebellion in Mindanao which prompted me to issue Proclamation 216… will not be quelled completely by 22nd July 2017 — the last day of 60-day period provided [by the Constitution],” he added.

The letter was sent to lawmakers on Monday night after Mr. Duterte met with them at the Palace, Presidential Spokesperson Ernesto C. Abella said in a press briefing on Tuesday.

Mr. Abella also said Mr. Duterte has called Congress to convene in a special session on July 22 to consider the extension of martial law.

“The primary objective of the possible extension is to allow our forces to continue with their operation, unhampered by deadlines, and to focus more on the liberation of Marawi and its rehabilitation and rebuilding,” Mr. Duterte’s spokesperson said.

“There is really a possibility that there is a looming situation in Mindanao,” he added.

The 1987 Constitution has set safeguards on martial law by limiting its enforcement to 60 days and allowing the Supreme Court and Congress to review the proclamation.

Asked if the military and police had proposed extending martial law to the remainder of 2017, Mr. Abella said: “They made recommendations and the President has made his own proposal.”

“The President has his own sources of information that prompted him to come to this conclusion… All of these things and whatever information he has, (this) is all related towards ensuring public safety,” he added.

The Executive’s plan to extend martial law came despite the military’s repeated assurance that soldiers “continue to gain headway” in operations in Marawi.

As of July 17, security forces have neutralized 413 extremists holed up in Marawi while government casualties reached 98. Forty-five civilians have been killed by jihadist bandits in the course of the bloody standoff, while nonstop air strikes and artillery bombings by advancing troops as well as deadly street combats have left the predominantly Muslim city in ruins.

Asked about whether the five-month extension of military rule is enough for troops to crush terrorists, Armed Forces of the Philippines (AFP) Chief-of-Staff Eduardo M. Año said this would depend on the developments “in the succeeding days.”

Mr. Año added that once the situation in Mindanao normalizes, the military would recommend the “early termination” of martial law.

He said government forces are still pursuing 60 to 70 Maute militants in Marawi and 800 Islamist fighters spread in Mindanao that are loyal to IS.