MANILA (Reuters) - The police chief of the Philippines on Wednesday stood by the head of a secretive unit behind dozens of killings in the country’s war on drugs, saying officers fired only in self-defence and the death toll reflected the danger and the scale of the narcotics problem.

FILE PHOTO: Philippine National Police (PNP) Director General Ronald Dela Rosa gestures during a news conference at the PNP headquarters in Quezon city, Metro Manila, Philippines January 23, 2017. REUTERS/Czar Dancel/File Photo

National police chief Ronald dela Rosa was responding to a Reuters Special Report that spent four months examining killings by one group of policemen from or near Davao City, the hometown of Philippine President Rodrigo Duterte.

Dela Rosa said police district 6 in Quezon City had Metro Manila’s most serious drug problem and he personally sent squad commander Lito Patay there because he was a “very professional” and “very dedicated” officer capable of dealing with it.

Patay handpicked and headed a unit of 10 men who called themselves the “Davao Boys”, which racked up the highest number of kills in Quezon City, a violent frontline in Duterte’s ferocious anti-narcotics campaign.

Police station 6 officers killed 108 people in anti-drug operations from July 2016 through June 2017, the campaign’s first year, accounting for 39 percent of Quezon City’s body count, according to official crime reports analyzed by Reuters.

A majority of the killings were carried out by the squad run by Patay, who was reassigned to Quezon City just a few weeks after Duterte unleashed his crackdown.

“He (Patay) was chosen because I have big trust in him, he has the balls to face the problems. He will fight,” dela Rosa told reporters.

“He is not an officer who is after money, who will be assigned in an area only to collect money, he is not that kind of officer. He has focus. I assigned him there because I know he can deliver.”

‘FREE HAND’

Asked about the high rate of killings in areas under Patay, he said deaths were inevitable where the drugs trade was rampant.

“So what’s the problem? The worst drug problem is there in station 6, so if you hit the problem head on, you face the problem head on then, there would always result in casualties,” he said.

Nearly 4,000 mostly urban poor Filipinos have been killed in anti-drug operations since July 2016. Police reject activists’ allegations they have executed drug users and peddlers and say they kill only when their lives are in danger.

Dela Rosa said Patay has since been reassigned to another province to make him eligible for promotion, reflecting his success in convincing drug suspects in Quezon City to surrender to the authorities.

He said Patay had been “given a free hand” at station 6 and had command responsibility over his operations.

“It is his own call whatever he does there, he has to solve the drug problem,” dela Rosa said.

The story of the Davao Boys also highlights a larger dynamic: Many of the drug war’s key police officers - dela Rosa included - hail from or served in Duterte’s hometown, where the campaign’s brutal methods originated during his time as mayor.

Duterte has repeatedly denied he ordered the killings of criminals and drug dealers during his 22 years as Davao mayor, or his 17 months as president.

Dela Rosa appeared frustrated when asked by a reporter if he personally had ordered the deaths of drug suspects in Quezon City. He said Patay’s men had no alternative but to kill armed criminals who refused to go quietly.

“He was placed there to address the drug problem, and not to kill those who deserved to be killed,” he said of Patay. “If they resist, why would you risk your life? You have to fight back.”