MANILA: Philippine President Rodrigo Duterte has threatened to impose martial rule to prosecute his deadly war on drugs, three decades after the nation shed dictatorship with a famous “People Power” revolt.

“If I wanted to, and it (the illegal drugs problem) will deteriorate into something really very virulent, I will declare martial law if I wanted to. No one will be able to stop me,” Duterte said in a speech on Saturday night.

The 71-year-old former state prosecutor said the aim would be “to preserve the Filipino people and the youth of this land.”

Duterte won elections in May last year on a pledge to wipe out illegal drugs, promising an unprecedented crackdown to stop the Philippines from becoming what he termed a narco state.

The crackdown has left at least 5,700 people dead in just over six months, raising concerns of a breakdown in the rule of law with security forces and vigilantes carrying out extrajudicial killings.

The Philippines’ longtime ally, the US, has led international criticism of the killings, with outgoing President Barack Obama urging Duterte to prosecute his war “the right way.”

Duterte has reacted furiously to the criticism and vowed to continue his war until illegal drugs are eradicated.

Duterte has raised the prospect of imposing martial law previously.

However Saturday’s comments were the most direct threat.

Martial rule would allow Duterte to use the military to enforce civilian law and detain people at length without charging them.

The Philippines last endured martial law during the 20-year rule of dictator Ferdinand Marcos, who was accused of plundering billions of dollars from state coffers and overseeing widespread human rights abuses.

Marcos declared martial law in 1972, invoking the threats of crime and a communist insurgency, and lifted it in 1981.

His rule ended in 1986, when millions took to the streets in the largely bloodless military-backed “People Power” revolt.

Separately, Duterte said he has ordered his troops to bomb extremists who flee with their captives in a bid to stop a wave of kidnappings at sea, calling the loss of civilian lives in such an attack “collateral damage.”

Duterte has previously stated that he had told his Indonesian and Malaysian counterparts their forces can blast away as they pursue militants who abduct sailors in waters where the three countries converge and bring their kidnap victims to the southern Philippines. He said in a speech late Saturday that he had given the same orders to Filipino forces.

He said he instructed the navy and the coast guard that “if there are kidnappers and they’re trying to escape, bomb them all.”

“They say ‘hostages.’ Sorry, collateral damage,” he said in a speech to business people in Davao, his southern hometown.

He said such an approach would enable the government to get even with the ransom-seeking militants. “You can’t gain mileage for your wrongdoing, I will really have you blasted,” he said.

His advice to potential victims? “So, really, don’t allow yourselves to be kidnapped.”

Duterte’s remarks reflect the alarm and desperation of the Philippines, along with Malaysia and Indonesia, in halting a series of ransom kidnappings primarily by Abu Sayyaf militants and their allies along a busy waterway for regional trade.