The Philippine president, Rodrigo Duterte, has repeated claims that he killed suspected criminals as he vowed no let-up in his war on drugs that has already claimed thousands of lives.

In an hour-long speech on Friday to Filipinos in Singapore, Duterte referred to international news coverage of his claims this week that in his previous role as mayor of a major southern city he killed suspects to set an example for police.

“To spare you embarrassment about the crawlers on television that have been running on CNN and even the BBC since yesterday that says Duterte admits killing or shooting the criminals: they were not mistaken,” he said.

People in the 6,500-strong crowd cheered as Duterte used his trademark strong language to promise his drug war would continue.

“Sons of whores I will really kill these idiots,” he said.

“My campaign on drugs will not end, until the end of my term six years from now when every drug pusher is [killed],” he said, making a throat-cutting gesture.

Speaking to Filipino journalists travelling with him in Singapore, Duterte said the killings he claims to have committed were part of legitimate operations against drug pushers.



Duterte said he had killed three men during a hostage-taking incident in Davao City where he was mayor for more than 20 years.



“It was not because I was walking around that I killed,” he said. “It was actually an event that was covered by the TV … I said I killed about three of them. I didn’t really know how many bullets from my gun went through inside their bodies.”

Duterte easily won presidential elections in May largely on a promise to eradicate illegal drugs in Filipino society by killing tens of thousands of people.

More than 5,000 people have been killed since Duterte took office in late June, leading to fears of mass extrajudicial killings and a breakdown in the rule of law.

Duterte’s comments this week about personally killing people when he was mayor triggered fresh expressions of concern from rights groups and the US government.

The White House press secretary, Josh Earnest, told reporters: “Those comments are deeply troubling, and they certainly are at odds with the Philippine government’s stated commitment to due process and rule of law.”

Long-running efforts by a United Nations rights rapporteur, Agnès Callamard, to investigate the drugs war hit another hurdle on Friday when she said she had rejected three conditions for her visit set by Duterte’s government.

Callamard said she had written to the government urging it to reconsider the conditions, which included a public debate with Duterte.

The Philippine foreign secretary, Perfecto Yasay, speaking to reporters in Singapore on Friday, said the government would not make any concessions.

“If she cannot comply with it [the Philippine conditions], then that’s the end of it,” Yasay said.

Duterte has repeatedly insisted neither he nor his security forces are breaking any laws in prosecuting the crime war. However, the president has publicly encouraged civilians to kill drug addicts and said he would not prosecute police for extrajudicial killings.

A report by the Guardian in October cited a senior officer in the police force who claimed he led one of 10 special operations teams, each with 16 members, tasked with killing suspected drug users, dealers and criminals.

The officer claimed the hit squads were composed of active police officers and that the murders were conducted in such a way as to make them appear to be perpetrated by vigilantes to deliberately obscure police involvement and preclude investigation.

The report was later denied by the chief of police. Duterte has insisted police are killing only in self-defence while gangsters are murdering the other victims.

Duterte’s aides and political supporters this week shrugged off his statements about personally killing people.

The justice secretary, Vitaliano Aguirre, said Duterte did not violate any law, and either was making up the claims or had only killed people in self-defence.

“The president always uses hyperbole, is always exaggerated to put his message across,” Aguirre said on Wednesday. “If the suspect fought back, he must have been forced to kill him.”

Surveys show many Filipinos endorse Duterte’s campaign, and some of those who turned up to listen to him in Singapore on Friday expressed sentiments felt by compatriots back home.

“When the president promises that he will solve the drugs and crime problem, it’s very hopeful for us,” said Eloisa Lopez, 50, a domestic worker who had taken time off to volunteer at the event.