GENEVA (AP) — A U.N. panel reported Thursday it believes the Syrian government is committing a crime against humanity by making people systematically vanish, and that rebels have also recently begun making their opponents disappear.

The expert panel said it found “a consistent country-wide pattern” of Syrian security, armed forces and pro-government militia seizing people in mass arrests or house searches and at checkpoints and hospitals, then making them disappear — and denying that they even exist. Most of the victims have been young men.