By Karen Lema

MANILA (Reuters) – The Philippines has recorded about 1,800 drug-related killings since President Rodrigo Duterte took office seven weeks ago and launched a war on narcotics, far higher than previously believed, according to police figures.

Philippine National Police Chief Ronald Dela Rosa told a Senate committee on Monday that 712 drug traffickers and users had been killed in police operations since July 1.

Police were also investigating 1,067 other drug-related killings, Dela Rosa said, without giving details. The comments came a day after Duterte lashed out at the United Nations for criticizing the wave of deaths.

As recently as Sunday, the number of suspected drug traffickers killed in Duterte’s war on drugs had been put at about 900 by Philippine officials. But this number included people who died since Duterte won the May 9 presidential election.

Duterte said in a bizarre and strongly worded late-night news conference on Sunday the Philippines might leave the United Nations and invite China and others to form a new global forum, accusing it of failing to fulfill its mandate. [L3N1B202G]

However, his foreign minister, Perfecto Yasay, said on Monday the Philippines would remain a U.N. member and described the president’s comments as expressions of “profound disappointment and frustration”.

“We are committed to the U.N. despite our numerous frustrations and disappointments with the international agency,” Yasay told a news conference.

Last week, two U.N. human rights experts urged Manila to stop the extra-judicial executions and killings.

Yasay said Duterte has promised to uphold human rights in the fight against drugs and has ordered the police to investigate and prosecute offenders. He criticized the U.N. rapporteurs for “jumping to an arbitrary conclusion that we have violated human rights of people”.

“It is highly irresponsible on their part to solely rely on such allegations based on information from unnamed sources without proper substantiation,” he said of the United Nations.

Senator Leila de Lima, a staunch critic of the president, started a two-day congressional inquiry into the killings on Monday, questioning top police and anti-narcotics officials to explain the “unprecedented” rise in killings.

“I am disturbed that we have killings left and right as breakfast every morning,” she said.

“My concern does not only revolve around the growing tally of killings reported by the police. What is particularly worrisome is that the campaign against drugs seems to be an excuse for some law enforcers and other elements like vigilantes to commit murder with impunity,” De Lima said.

(Editing by Raju Gopalakrishnan)