The raid on the suspected drug users was conducted in a slum of Binondo district on Monday, Efe news reported.
According to police reports, the suspects were caught consuming drugs and while opposing the arrest they were killed.
One of the suspect was taken to a hospital in critical condition but died later.
Families of the suspects denied any of their involvement in drugs.
Some locals blamed the police of "extrajudicial killings of the suspects in the name of drug policy".
The slaying of the suspects included 21 persons killed since Saturday in the ongoing anti-drugs campaign, taking the total count of people killed to 1,487 since Duterte's war on drugs began on July 1, according to police.
Police have undertaken 17,679 operations in the campaign since July 1, and 16,442 drug suspects were arrested and 7,10,555 surrendered, highlighting the spread of drug menace in the country.
