“The killings committed by [President Duterte of the Philippines], by his own admission, at a time when he was a mayor, clearly constitute murder,” said the UN High Commissioner for Human Rights, Zeid Ra'ad Al Hussein.

“It should be unthinkable for any functioning judicial system not to launch investigative and judicial proceedings when someone has openly admitted being a killer,” he added.

According to the UN human rights arm, Duterte told business leaders last week that he had patrolled the streets personally on his motorcycle and killed people. On Friday, in an interview with the BBC, he confirmed that he had personally killed “about three” people during his term as the mayor of Davao.

“The killings described by President Duterte also violate international law, including the right to life, freedom from violence and force, due process and fair trial, equal protection before the law, and innocence until proven guilty,” underscored High Commissioner Zeid, adding that if Duterte, as a government official, encouraged others to follow his example, he may also have committed incitement to violence.

Zeid also said that Duterte's repeated calls for the police, military and the general public to engage in a 'war on drugs', bringing people in 'dead or alive', has emboldened an environment of alarming impunity and violence and that repeated statements indicating immunity for police officers who engaged in human rights violations in the line of duty were “a direct violation of all democratic safeguards that have been established to uphold justice and the rule of law.”

The High Commissioner's Office (OHCHR) said that since Duterte's assumed presidency on 30 June, more than 6,100 people have reportedly been killed either by police, or by vigilantes and mercenaries, apparently acting in response to the President's 'war on drugs.'

“In his public comments last week, Duterte promised 'For as long as there are drug lords, this campaign will go on until the last day of my term and until all of them are killed.',” OHCHR noted.

“Credible and independent investigations must be urgently re-opened into the killings in Davao, as well as into the shocking number of killings that have occurred across the country since Duterte became president,” underlined the UN human rights chief, stressing:

“The perpetrators must be brought to justice, sending a strong message that violence, killings and human rights violations will not be tolerated by the State and that no one is above the law.”

Zeid also called on the Government to lift a series of preconditions it imposed on a planned visit by the UN Special Rapporteur on summary executions to investigate alleged extra-judicial killings of suspected drug dealers.