Crimes against humanity and war crimes by Myanmar’s military have escalated at an “alarming” rate, United Nations investigators have warned.

Systematic torture, gang rape and abuses against children have increased under the military, the UN body investigating human rights violations in the country said in its annual report on Tuesday.

Investigators said that more than three million people have been forced to flee their homes in the last six months, as the conflict intensified.

“We have collected substantial evidence showing horrific levels of brutality and inhumanity across Myanmar,” said Nicholas Koumjian, the head of the UN’s Independent Investigative Mechanism for Myanmar (IIMM).