MANILA, Oct 28 (Reuters) - Former Philippine President Rodrigo Duterte confirmed a "death squad" existed under his watch to control crime when he was Davao City mayor, but gave conflicting accounts of its makeup, first saying it was run by police officers, then by gangsters.

When Duterte was president, two men including a former policeman had testified before the Senate they were part of an alleged hit squad in Davao they said killed at Duterte's behest, but legislators at the time found no proof and Duterte's aides dismissed the claims as fabrication.

Appearing on Monday before a Senate inquiry into his campaign against illegal drugs, Duterte identified "commanders" of the death squad which he said included former national police chief-turned senator Ronaldo dela Rosa, who was also present at the hearing.

"That is the job of the police," said Duterte, who admitted to senators thousands of criminals died when he was Davao mayor.

He said he had never ordered the death squad to kill defenceless suspects, but did tell the group "to encourage criminals to fight back, and when they fought back, kill them so my problems in the city will be solved."

But the 79 year-old Duterte later said gangsters - not police - made up his death squad, adding to the ambiguity surrounding the squad's operations.

"I can make the confession now if you want," Duterte said. "I had a death squad of seven, but they were not police, they were gangsters."

Human rights groups documented about 1,400 suspicious killings in Davao during the 22 years Duterte was mayor and critics say the war on drugs he unleashed as president bore the same hallmarks.

More than 6,200 people were killed in police operations in the drugs campaign, which is also the subject of an International Criminal Court investigation.

Police reject allegations the killings were executions, saying the drug suspects violently resisted arrest and that authorities acted in self-defence.

Senator dela Rosa, who oversaw Duterte's bloody crackdown when he was national police chief, previously said the death squads were "fiction." In the hearing on Monday, he downplayed Duterte's remarks, saying they should be taken as a joke.