A plane carrying former Philippine leader Rodrigo Duterte to the International Criminal Court to face charges over his bloody "war on drugs" took off for Rotterdam on Wednesday, after being delayed by a few hours during a layover in Dubai.

Duterte, who led the Philippines from 2016 to 2022, was arrested early on Tuesday in Manila, marking the biggest step yet in the ICC's probe into alleged crimes against humanity during an anti-drugs crackdown that killed thousands and drew condemnation around the world.

Duterte, 79, could become the first Asian former head of state to go on trial at the ICC in The Hague.

The ICC's warrant for his arrest says that as president, Duterte created, funded and armed "death squads" in his war on drugs that carried out murders of purported drug users and dealers.

In coming days, he will be brought before a judge and will have the allegations read out in court. Prosecutors accuse him of crimes against humanity for systematic attacks that led to dozens of murders.