MANILA - At least two Catholic bishops have voiced concern after government's fierce war on drugs recorded its bloodiest week by far, with dozens slain in anti-narcotics operations in Metro Manila and Bulacan.

Bishop Jose Oliveros of the Diocese of Malolos, which covers Bulacan province and Valenzuela City, said he is alarmed by the increasing number of drug-related killings.

"We are all concerned about the number of drug related killings in the province because they are mostly, if not all, extrajudicial killings," Oliveros said in a report on CBCP News.

The prelate also questioned the motive of the police.

"We do not know the motivation of the police why they had to do the killings in one day, maybe to impress the President who wanted more," he added.

Caloocan Bishop Pablo Virgilio David also questioned the rising number of killings under the government's crackdown against illegal drugs.

He likened today's killings to cases during the Marcos dictatorship, when the tag "communist" was the "convenient label and justification" for atrocities committed by law enforcers.

"Now, it's 'drug suspects,'" David said. "I don't know of any law in any civilized society that says a person deserves to die because he or she is a 'drug suspect.'"

On Wednesday, in Bulacan alone, 32 were killed within 24 hours in province-wide simultaneous anti-drug operations.

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In the nearby city of Caloocan, Kian Loyd Delos Santos, a 17-year old student, was killed in an anti-illegal drug raid, sparking outrage from his family and neighbors who insist that he was innocent.

Surveillance footage which caught the incident, however, suggested that the minor had already surrendered to police before he was shot dead.

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Malacañang called the incident "isolated" and said it would not tolerate police abuse.

Less than 24 hours after, at least 25 people were killed in various anti-crime raids in Manila.

Despite the killings, Malacañang asserted that more people have come to appreciate President Rodrigo Duterte's campaign because it has made the streets safer.

The Catholic Bishops Conference of the Philippines has repeatedly criticized the government's war on illegal drugs. In retaliation, the President has many times lashed out at the Church hierarchy, calling them hypocrites and corrupt.