DAVAO, Philippines - Davao City Mayor Rodrigo Duterte has admitted his links to the Davao Death Squad, which is allegedly responsible for summary executions of criminals in the city. He also warned he will kill up to 100,000 criminals if he is elected president.

The New York-based Human Rights Watch has called for an investigation into the Davao Death Squad killings and urged the Philippine government not to tolerate a public official who endorses extrajudicial killings.

In a television interview, Duterte was unapologetic about his actions and even dared the group to file a case against him in court.

"Ako, ako daw death squad? True, that's true," he said in an interview with Gikan sa Masa Para sa Masa.

"Gusto ko sila pumunta dito. There's no need for you to go to the Ombudsman. There is no requirement that you go to the human rights. File directly in court. Then I'll place you under oath. Just execute an affidavit. Then I'll call you when it's my time for cross-examination. And I will show to the world how stupid you are," he added.

Human Rights Watch earlier denounced the more than 1,000 killings committed by the Davao Death Squad since the late 1990s. Police and local government officials were reported to be involved in the targeted killings of alleged drug dealers and petty criminals, street children and others.

Duterte himself has boasted that Davao has become one of the world's safest cities simply by killing all criminals.

A Commission on Human Rights investigation in 2012 found probable cause to recommend that the Office of the Ombudsman file murder charges against the mayor. The Ombudsman, however, limited its investigation to police officers linked to the killings and found 21 guilty of "simple neglect of duty."

Duterte said the summary executions is one of the reasons he doesn't want to run for higher office in 2016. Duterte ranked 3rd in a recent Social Weather Stations survey on presidential contenders.

He also said that instead of 1,000 dead criminals, the number might rise to 50,000 dead if he is elected president.

"Alam po pag ako ang presidente, I will warn you I do not covet the position. Pag naging presidente ako, magtago na kayo. Yung 1,000 n ayan it would reach 50,000. I will kill all you [expletive] breaking the life of the Filipino miserable. Papatayin ko talaga kayo."

"Manalo ako kasi because of breakdown of law and order. I do not want to commit a crime but if by chance, God will place me there, magbantay kayo. Yung 1,000, magiging 100,000. Dyan mo makita tataba yung isda sa Manila Bay. Dyan ko kayo itapon."

"I do not want to be president. I do not want to kill people so do not elect me as president."