Five people were killed inside their homes in Quezon and Navotas cities, reports said on Sunday.
A radio dzBB report said four people were founded dead inside a shanty home in Barangay Payatas B in Quezon City.
The victims were identified as Criselda Chua, Anthony Salazar, Leo Barba, and Celso Cervantes.
Barangay tanod Nicanor Silanga said a concerned citizen informed them on Sunday morning about an indiscriminate firing at house number 111 along Golden Hills Street corner Chocolate Hills.
Silanga said the concerned citizen told them gunshots were heard from the area at around 11:40 p.m. Saturday.
Residents in the area said that the house is being used as a drug den.
Police found several drug paraphernalia, including four aluminum foils and a lighter, in the house.
Meanwhile, construction worker Orlando Caballero, 36, was killed by six unidentified gunmen at around 2 a.m. Sunday inside his home in Barangay Tumana, Navotas City.
A separate radio dzBB report witnesses saw Caballero being dragged out of his home before he was killed by the gunmen.
The victim's family said they did not know the possible reason for Caballero's killing and they denied that he was involved in illegal drugs.
The National Capital Region Police Office on Friday shared to the media a Pulse Asia survey, which shows 82 percent of residents in Metro Manila "feel safer" due to its anti-drugs campaign.
The survey was conducted from December 6 to 11, 2016, five months after President Rodrigo Duterte declared the war on drugs. Respondents were randomly selected and were asked the question: “Compared to last year, I feel that it is less dangerous now in our place because of the campaign against illegal drugs.” —Joseph Tristan Roxas/ALG, GMA News