MANILA - The Philippine National Police on Monday relaunched its door-to-door anti-drug drive after a near four-month hiatus, saying it was "impossible" to avoid bloodshed when suspects fight back.

With the revival of "Oplan Tokhang," the Catholic Bishops' Conference of the Philippines urged the PNP to avoid a further "waste of lives."

Under the new "Tokhang" guidelines, police who go from house to house seeking suspects' surrender can only do so during office hours. Should the suspect refuse to surrender, he or she will be referred to a separate police team for case build-up.

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The rule of law will "always prevail" in all anti-narcotics efforts, but the results will depend on the reaction of suspects, said PNP chief Director General Ronald Dela Rosa.

"Alangan namang pabayaan namin ang mga sarili namin na mamatay kami kung armado at makipagbarilan ang drug personalities?," he told reporters.

(Will we allow ourselves to be killed if drug personalities are armed and engage us in a gun fight?)

"I cannot give you a 100-percent or foolproof anti-drug campaign na magiging bloodless... Kung mayroon tao dyan [na sabihing], 'Maging successful tayo sa anti-drugs na walang mamamatay,' that's baloney, that's impossible," he added.

(I cannot give you a 100-percent or foolproof anti-drug campaign that will be bloodless. If someone says, 'Our anti-drugs campaign can be successful without anyone dying,' that's baloney, that's impossible.)

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Human rights groups have claimed that some 12,000 drug suspects have died since President Rodrigo Duterte launched his war on drugs in 2016. Data from the PNP places the death toll at nearly 4,000.

Officials have maintained that suspects killed in police operations fought back.

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"We pray that the police follow the prescribed steps in implementing the law… steps that should be done in exercising their responsibility as policemen," CBCP president Romulo Valles, the Archbishop of Davao, was quoted as saying by CBCP News.

"Let us inspire them to follow the necessary steps when they need to apprehend and as much as possible, we make sure that we do not waste any lives," he added.

Stricter guidelines for anti-drug operatives were released months after President Rodrigo Duterte allowed the police force to rejoin the government's anti-drug efforts.

"Oplan Tokhang" was suspended in October following the death of teenager Kian delos Santos, whom police accused of being a drug courier.