A human rights law group contracted by the U.S. State Department to investigate atrocities against Rohingya Muslims in Myanmar said on Monday there was an urgent need to establish a criminal tribunal to bring those responsible to justice.

A report released on Monday by the Washington-based Public International Law and Policy Group (PILPG), based on more than 1,000 interviews with Rohingya refugees who fled to Bangladesh, said there were reasonable grounds to believe the Myanmar military committed crimes against humanity, genocide and war crimes against the minority group.

"The international community is obliged to protect populations subjected to atrocity crimes by the own governments and ensure justice and accountability for such crimes," the report said.