MANILA (Kyodo) -- Former Philippine President Rodrigo Duterte on Friday faced the International Criminal Court over charges of murder as a crime against humanity in relation to his government's crackdown on illegal drugs, the tribunal said.

Duterte, who was transferred to The Hague after being arrested at an airport in Manila on Tuesday, participated in the hearing via video link, during which his identity was verified and he was informed of his alleged crimes and rights.

The court set a hearing for Sept. 23 to determine whether there is substantial evidence for the charges before a trial begins.

The ICC said Duterte, 79, is accused of being an "indirect co-perpetrator" of the alleged killings in the country between 2011 and 2019. Duterte ended his six-year presidency in 2022.

"I am so mad. He was the reason our lives were upended," said Jane Lee, 42, whose husband was killed in 2017 amid the crackdown although she denied he had ever used drugs.

Lee and other family members of victims watched Duterte's court appearance on a projector screen in Manila.

"I hope he never returns to the Philippines," she said.

Meanwhile, Duterte's supporters have since held rallies and criticized Philippine President Ferdinand Marcos Jr. for surrendering his predecessor.