The police have claimed responsibility for the deaths of 600 drug suspects since the start of July
The UN has urged the new president of the Philippines to end a wave of extra-judicial killings, carried across the country as part of a radical anti-drug campaign.
It comes as the country's police revealed they were responsible for the deaths of nearly 600 drug suspects since the start of July.
Local media reports suggest the true number could be well over 1,000, when killings apparently carried out by vigilante gangs are taken into account.
The drive began the moment Rodrigo Duterte took office seven weeks ago, after a landslide election victory, won on a promise to launch a "bloody war" against drugs.
Since then more than half a million addicts and pushers have "surrendered" to authorities, signing contracts and undertaking oaths to stop using drugs.
The surrenders are obtained during so-called "knock and ask" operations, often in some of the country's poorest neighbourhoods, where methamphetamine use is rife.
Officers in the Smoky Mountain police district of Manila's Tondo slums went door-to-door, checking on people who had previously "surrendered" and admitted being drug users.
In that district alone, more than 20 drug suspects have been killed in recent weeks. Inspector Monico Aliado, said: "If the life of the police is in danger, I will kill them".
When asked if he ever had second thoughts, or worried people might be innocent he replied: "I worry about the innocent, about the children, as the case may be, but if the drug personalities fight back … I'll kill them."
His message was in-line with the position of his President.
During a speech at a police ceremony in Quezon City this week, Mr Duterte mocked the UN - saying they should deal with the conflict in the Middle East before criticising him - and told officers he would stand trial on their behalf if they were accused of unlawful killing.
"If their resistance is violent, if you fear for your life when making an arrest, shoot him, and shoot him dead - can I be clearer than that?", Mr Duterte said, while addressing officers.
But for the families of those killed, big questions remain.
Marissa Resido, a mother of six from the Tondo slums, told Sky News that her husband Rolando was a meth user, and was killed by police hours after they took him away to "surrender".
"They told us that they were just going to take him away to sign something and talk to him … I was just shocked when we found out what happened to him. My husband wasn't a bad guy, not for them to do that to them," she said.
But in the very neighbourhood where the Residos live, there was clear evidence of strong support for the President's hardline campaign.
Above one of the dark alleyways hung a sign reading "drug free zone - user and pushers do not enter".
Elizabeth, who was running a small fish stall, was cheered as she told Sky News: "Oh yes, there are far fewer addicts now … he's good, Duterte is doing a good job - it's really good for our country."
President Duterte's campaign is based on the similarly ruthless approach he took to tackle crime in the southern city of Davao, where he was mayor for over two decades.
But the calls for restraint are growing, not just from the international community, but from within the Philippines as well.
Former justice secretary Senator Leila De Lima is planning to launch an inquiry into the killings - an act that has already drawn scorn from the President, who labelled her an "immoral woman".
She said the popularity of the extra-judicial killings was a reflection of a deeper problem.
"There are misfits in all the structures of our government - law enforcers, prosecutors and judges. That's why our justice system is broken, and that is why these shortcuts are being encouraged," Senator De Lima said.
But Mr Duterte's seems determined to continue - pledging to double police salaries by the end of the year, and put meth-addicts, who he described as being "no longer viable as human beings", in 'rehab camps' on military bases.