Families and relatives of victims of the Duterte administration's drug war hold a protest in front of the Senate Gate in Pasay City on Monday while former president Rodrigo Duterte makes a rare appearance before a Senate committee hearing investigating his war on drugs.

Duterte said he takes "full responsibility" for the bloody anti-narcotics campaign, but also denied that killing was policy. Duterte claimed that he had "always viewed people addicted to illegal drugs as victims and patients requiring medical help and not as criminals."

Human rights groups in the Philippines and abroad have flagged abuses in Duterte's drug war, saying policemen killed with impunity.