A London-based people’s tribunal investigating whether China’s treatment of Muslims amounts to genocide opened on Friday with witness testimony detailing mass torture, rape and a range of other abuses.

The first hearings take place over four days, from Friday to Monday, and are expected to draw dozens of witnesses.

A second session is expected in September.

The nine UK-based jurors of the tribunal, including lawyers and human rights experts, intend to publish a report in December on whether China is guilty of genocide.

Organizers hope the process of publicly laying out evidence of an alleged state-orchestrated campaign of repression against Muslims will compel international action against the country’s authorities.

According to United Nations, at least one million Muslims have been detained in the internment camps which border eight countries including Afghanistan, Pakistan and India.