Catholic bishops in the Philippines condemned the sharp rise in police killings in the country days before President-elect Rodrigo Duterte takes office.

In Monday's pastoral message addressed to Philippine law enforcers, the Catholic Bishops Conference of the Philippines (CBCP) also called on Christians in the country to ask themselves if they have contributed to the spread of crime by their acts or by their silence, the Vatican Radio reports.

Duterte has repeatedly threatened to eradicate crime, encouraging the police and even private gun owners to arrest suspected drug pushers and other criminals and shoot them dead if they resist arrest.

In their statement, the bishops cited reports that as a result of Duterte's call for vigilantism, bodies are piling up with labels declaring their supposed crime.

Without mentioning Duterte's name, the bishops condemned such call for vigilantism, saying every Christian should turn away from such movements.

They also condemned the incoming president's offer of financial bonuses to police who kill crime suspects, saying such bounties are not morally acceptable.

Over the weekend, the Cardinal of Manila, Luis Antonio Tagle, issued a special prayer for public officials. It quotes St. Paul's Letter to Timothy, urging people to pray for those in office so that they may live "quiet lives, godly and dignified in every way."

The prayer is to be used at Masses up until Duterte takes office on June 30.

This weekend, the Philippine National Police reported that it has killed 11 suspected drug dealers during operations, adding to the growing list of police killings since Duterte rose to power last month on promises to wipe out crime.

Although Duterte's sole campaign promise of tackling illegal drugs and other crime within six months won him the hearts of Filipino voters, the Church and rights groups have expressed alarm over concerns that, as president, he would live up to his nickname of "the punisher."

More than 40 drug suspects have been killed since Duterte won the May 9 election. In comparison, only 39 deaths were recorded in the four months before May, a police spokesman told Reuters.

Speculation is spreading in Manila that some police officers involved in the drugs business have been "clearing the decks" before Duterte takes office by eliminating criminals who could implicate them. Duterte has also promised an iron hand to deal with law enforcers with links to drug and other crime syndicates.