MANILA — The Department of Justice has directed the National Bureau of Investigation to probe the death of 17-year-old Kian Loyd Delos Santos.

In a department order issued Friday, Justice Secretary Vitaliano Aguirre instructed the NBI to investigate and put together a case build-up on the death of Delos Santos, who was killed in an anti-illegal drugs operation in Caloocan City on Wednesday.

READ: DOJ orders NBI to probe death of Kian Loyd delos Santos | via @InaReformina pic.twitter.com/K1HdAGXARz

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A Grade 11 student, Delos Santos was killed after police alleged that he shot at the officers, prompting them to fire back.

Surveillance footage showed 2 officers accompanying Delos Santos to the spot where the boy was killed. A witness alleged that the police beat up the victim, gave him a gun by force, and told Delos Santos to run for his life.

Metro Manila police chief Director Oscar Albayalde has vowed an impartial investigation into Delos Santos' death, a killing that has sparked outrage over the conduct of police operations.

• Palace on 17-year-old's death in Caloocan: An 'isolated' case

The slain teen's family on Saturday met with Senator Risa Hontiveros, who said she is willing to assist the family, such as helping them to be under witness protection.

Hontiveros also requested for a certified true copy of the CCTV footage.

• READ: Binatilyo, patay nang 'manlaban' sa pulis; pero iba ang kuha sa CCTV

The Caloocan chief of police and his men who were linked to Delos Santos' death have been relieved of their positions, Albayalde said.

Senator Bam Aquino said he plans to file a resolution for the Senate to investigate Delos Santos’ death.

Senator Antonio Trillanes IV, meanwhile, called on the Senate to hold a caucus on Tuesday to discuss the increasing number of deaths in raids conducted by police under the anti-illegal drugs campaign.

"Sobra na. Maling-mali na talaga to. I cannot, in conscience, let this pass. The senators should have a united stand to stop this," Trillanes said.

This week, overnight anti-illegal drug operations in Bulacan left 32 dead, while 25 were killed in Manila, and 17 were killed in Caloocan.

• READ: Kaliwa't kanang imbestigasyon, nais ikasa dahil kay Kian

Meanwhile, a child rights group condemned the killing of Delos Santos and said the Duterte administration's campaign against illegal narcotics "has taken many innocent lives, including those of children."

"Any efforts to pursue peace and order should never be at the expense of human rights and rule of law, and should always uphold the best interests of Filipino children. #JusticeForKian," Child Rights Network said in a statement.