Police in the Philippines resumed president Rodrigo Duterte's war on drugs on Monday, making visits to the homes of users and dealers to convince them to surrender, but force's chief said he could not promise a bloodless campaign.
The announcement came as the justice department filed its first criminal case against police officers involved in the battle against drugs, bolstering human rights activists' accusations of fabricated accounts of shoot-outs with drug suspects.
The home visits, known as "Oplan Tokhang", made a comeback with an assurance from national police chief Ronaldo dela Rosa that it should be free of violence if offenders agreed to go quietly and did not resist.
But he said he could not promise a "foolproof anti-drug campaign that would be bloodless" as the police were "not dealing with people who are in their proper state of mind".
"What if after knocking, the door opens and grenades are hurled out?" Mr Dela Rosa asked. "That has happened in the past so instead of tokhang, there were gunfights."
In the dialect of Mr Duterte's southern hometown of Davao, "Tokhang" is a combination of the words "knock" and "plead".
Besides the visits, police have also run so-called "buy-bust" or sting operations and raided suspected drug dens and illicit laboratories.
In many of these operations, rights activists say, suspects were executed in cold blood without being given the chance to surrender. But police insist suspects died because they violently resisted arrest.
Nearly 4,000 drug suspects have been killed by police since June 2016, when Mr Duterte came to power, while police data shows that 85 police and soldiers have been killed in the war on drugs.
More than 1.2 million people had also turned themselves in after the home visits.
Mr Duterte has stopped police anti-drugs operations twice due to questions over the conduct of the force, including the killing of a teenager in a supposed anti-drug operation.
On Monday, the justice department filed murder charges and two drug-related cases against three police officers who killed the teenager, Kian Loyd delos Santos, after witnesses disputed the police version of the killing.
National police spokesman Dionardo Carlos said the force welcomed the filing.
"The police officers have to face their accusers in court and prove their innocence, they have to follow the procedures," he said, urging due process for the officers.
To ensure transparency, police chief Mr Dela Rosa invited human rights advocates, priests and the media to join the relaunched home visits.
The police officers involved would also undergo a vetting process to weed out "rogue" officers, said Mr Dela Rosa, adding that past abuses had involved the police seeking bribes to drop people from the lists they compiled.
"We are certainly hoping that it will be less controversial, because controversy will only blur the real intention, which is really the fight against dangerous drugs," said Harry Roque, Mr Duterte's spokesman.