LOOK: Protesters gather outside the International Criminal Court (ICC) in The Hague, Netherlands, during the opening of former President Rodrigo Duterte's pre-trial hearing for crimes against humanity allegedly committed during his deadly crackdown on narcotics.

Duterte, however, did not attend the hearing in person. He appeared via video link, speaking briefly to confirm his name and date of birth.

The 79-year-old is accused of the crime against humanity of murder over his years-long campaign against drug users and dealers, which human rights groups claim resulted in over 30,000 deaths.

Protesters welcomed the trial as a step toward justice, while Duterte’s supporters argue he was "kidnapped."