Philippines' Catholic bishops have rebuked President Rodrigo Duterte's war on drugs, marking their toughest challenge yet to his policy that has led to the deaths of more than 7,000 people in the last seven months.

The Catholic Bishops' Conference of the Philippines in a pastoral letter read out in Sunday sermons called Duterte's antinarcotics campaign a "reign of terror in many places of the poor," reports The Wall Street Journal.

They called for resistance to a wave of apparent executions by police and vigilantes and said that not speaking out on the matter is tantamount to complicity, Vatican Radio reports.

While acknowledging that illegal drug trafficking needs to be stopped, "the solution does not lie in the killing of suspected drug users" and dealers said the bishops.

Duterte, who has been likened to U.S. President Donald Trump in the way he responds to his critics, dismissed the accusations with his customary bravado.

"You Catholics, if you believe in your priests and bishops, you stay with them. If you want to go to heaven, then go to them," he said. "Now, if you want to end drugs ... I will go to hell. Come join me," Duterte added.

The Catholic bishops wrote in their Jan. 30 letter that you "cannot correct a wrong by doing another wrong. A good purpose is not a justification for using evil means."

This pastoral letter was seen an effort to move public opinion in the southeast Asian archipelago a country where more than 80 percent of the population identifies as Catholic, Crux News said.

Many are killed not because of drugs, the bishops wrote. And those who kill them are not brought to account.

'INDIFFERENCE OF MANY'

The bishops added: An even greater concern is the "indifference" of many to what is going on.

"To keep silent in front of evil is to be an accomplice," they said.

There have been more than 7,000 recorded killings in only seven months, since President Duterte launched a campaign against drug pushers and users.

There have been reports of bounties paid to police officers who kill, and last week Amnesty International accused police of hiring contract killers.

Philippine police, "acting on instructions from the very top of government," gunned down and enlisted others to kill thousands of alleged drug offenders in a wave of extrajudicial executions that may amount to crimes against humanity, Amnesty International said in a report released Feb. 1.

AI's investigation is entitled, "If you are poor you are killed:" Extrajudicial Executions in the Philippines' "War on Drugs".

It details how police "have systematically targeted mostly poor and defenseless people" across the country while planting "evidence," recruiting paid killers, stealing from the people they kill and fabricating official incident reports.

Quoting a police officer involved in the war on drugs, AI reported that police received from 8,000 Philippine pesos ($160) to 15,000 pesos ($300) as incentive for every drug personality they killed.

"This is not a war on drugs, but a war on the poor. Often on the flimsiest of evidence, people accused of using or selling drugs are being killed for cash in an economy of murder," said Tirana Hassan, Amnesty International's Crisis Response Director.

"Under President Duterte's rule, the national police are breaking laws they are supposed to uphold while profiting from the murder of impoverished people the government was supposed to be uplift.

"The same streets Duterte vowed to rid of crime are now filled with bodies of people illegally killed by his own police."