Former Philippine president Rodrigo Duterte was arrested Tuesday, March 11, in Manila by police acting on an International Criminal Court (ICC) warrant citing crimes against humanity tied to his deadly war on drugs.

The 79-year-old faces a charge of “the crime against humanity of murder,” according to the ICC, for a crackdown in which rights groups estimate tens of thousands of mostly poor men were killed by officers and vigilantes, often without proof they were linked to drugs.