The International Criminal Court in the Hague has taken into custody a man wanted for war crimes in Mali, after the authorities there handed him over.
Al Hassan Ag Abdoul Aziz Ag Mohamed Ag Mahmoud headed the Islamic police in Timbuktu when it was under the control of jihadist militants five years ago.
He is accused of victimising women and girls by approving their forced marriages to Islamist fighters.
He is also alleged to have helped destroy ancient mausoleums in Timbuktu.
The arrest warrant for Mr Al Hassan listed crimes against humanity including "torture, rape and sexual slavery; persecution of the inhabitants of Timbuktu on religious and gender grounds; and other inhumane acts".
The only other man tried by the ICC over Mali's conflict admitted destroying cultural sites in Timbuktu at a landmark trial in 2016.
What happened at the previous trial?
Ahmad al-Faqi al-Mahdi pleaded guilty to destroying nine mausoleums and a mosque, in the first case of cultural desecration heard by the ICC.
It was the first time a suspected Islamist militant had stood trial at the war crimes court, and the first time a suspect had pleaded guilty.
Prosecutors said Mahdi was a member of Ansar Dine, an Islamist group that occupied Timbuktu for months.
He was jailed for nine years, after declaring he was "really sorry" for his actions and asking for forgiveness. In 2017 ICC judges found him liable for nearly €3m (£2.6m; $3,6m) in damages.
There is a chance he could now testify as a witness against Mr Hassan, Reuters news agency reports.
Mr Hassan's initial court appearance is scheduled for next week but he will not be required to enter a plea.