MANILA (Reuters) - Philippine leader Rodrigo Duterte called a top U.N. official an “idiot” and “joker” on Thursday for urging that murder investigations be launched against the president after he admitted personally killing people.

President Rodrigo Duterte at Clark Freeport Zone in Pampanga, Philippines December 22, 2016. REUTERS/Erik De Castro

Zeid Ra’ad Al Hussein, U.N. High Commissioner for Human Rights, on Tuesday said Philippine judicial authorities should probe Duterte’s accounts of having carried out killings when he was mayor of Davao City.

“This guy (Zeid) is ever the joker or crazy,” Duterte said during a televised speech, and repeatedly called him “stupid”.

“You U.N. officials, sitting there on your asses, we pay you your salaries. You idiot, do not tell me what to do ... Who gave you the right?”

Duterte told businessmen last week that when mayor he “personally” killed criminals on the streets and later admitted shooting dead three men involved in a kidnapping case, during a police gunfight in the late 1980s.

Zeid on Tuesday said investigations should also be opened into deadly anti-drugs campaigns in Davao when Duterte was mayor and the “shocking” number of deaths during the current nationwide campaign.

More than 6,000 people have been killed as part of Duterte’s crackdown, a third by police and the rest still officially under investigation. Duterte says the shootings by police were in self-defense.

Duterte has previously threatened to withdraw from the U.N. and called it “inutile” for being slow to respond to crises.

“Please shut up because your brain is lacking there,” he told Zeid.

“Go back to school. You United Nations, you do not know diplomacy. You do not know how to behave to be an employee of the United Nations.

“You do not talk to me like that, you son of a bitch.”