Philippine President Rodrigo Duterte has likened the nation's human rights commissioner to a "paedophile" for expressing concern over the police killing teenagers in the leader's ongoing war on drugs.

Police have reported killing more than 3,800 people in anti-drug operations since Duterte took office 15 months ago, while thousands of others have been murdered in unexplained circumstances.

The recent deaths of two teenagers have fuelled rising opposition to the campaign, with the influential Catholic Church and leftist activists among the most prominent critics.

During a speech late Saturday, Duterte turned on Jose Luis Gascon, the head of the Commission on Human Rights.

"That Gascon, how many days has he been saying: 'teenager, teenager'? He is like a paedophile, that son of a whore." Duterte said, 

"Why are you so interested in teenagers? Are you (a paedophile?) I am questioning this. Are you gay or a paedophile?"

Duterte also insisted that killing children was not exceptional, as he accused the rights chiefs and other critics of using the teenagers' deaths as part of a political opposition campaign.

"Teenager, teenager, son of a whore, it is all politics. Why can't you move on to other issues that are besetting this country," Duterte said, referring to an insurgency conducted by Islamic militants in the south of the country.

"Just because a kid was killed? That happens everywhere."

The policemen involved in the teenagers' deaths initially said they killed them in self defence. 

However, the National Bureau of Investigation said the policemen murdered one of the boys and planted a gun on him, and are still investigating the death of the other teenager.

Public attorneys allege that police also murdered the other boy.

The Commission on Human Rights responded to Duterte by saying "remarks such as these are unhelpful and deviate the public's attention  away from critical human rights issues".

"The death of children concerns us all as they are especially vulnerable and need state protection," the statement from commission spokeswoman Jacqueline de Guia said.

Duterte won last year's presidential election on a law-and-order platform in which he promised an unprecedented campaign to eradicate illegal drugs in society by killing up to 100,000 traffickers and addicts.

Many Filipinos back the drug war, seeing it as a quick solution to widespread crime, according to a series of polls over the past year. 

Duterte and his aides frequently seek to discredit or disempower critics of the drug war.

Duterte's allies in the lower house of Congress last week voted to cut the annual budget of the Commission on Human Rights, a body mandated under the constitution, from $13.5 million to just $20.

Source: AFP