Myanmar security forces have found a mass grave on the edge of a village in the Rakhine state and are investigating it, the country’s army said on Monday, Reuters reported.

For months now, the United Nations has been accusing Myanmar’s troops of committing atrocities against the Rohingya Muslim population in that region, after a militant attack in August got security forces conducting a violent crackdown in the state.

At least 6,50,000 Rohingya Muslims were forced to flee to Bangladesh in the past few months, where they now live in crowded refugee camps.

The army posted a statement about the mass graves on the Facebook page of the military’s commander-in-chief, Senior General Min Aung Hlaing. It said unidentified bodies had been found at a cemetery in the village of Inn Din, 50 km north of the state capital Sittwe.

The army said it acted on a tip-off from “someone who asked not to be named”. It did not say how many bodies were found or what community they belonged to, but added that “strong legal action will be taken if any member of security forces are involved,” AFP reported.

Ever since violence broke out in the region, the United Nations and several other human rights groups have accused Myanmar of a systematic ethnic cleansing campaign against the Muslim minority.

On Tuesday, Human Rights Watch released a report that said the army had carried out “systematic killings and rape” of hundreds of Rohingya in the Tula Toli village in northern Rakhine on August 30.

Last week, international humanitarian organisation, Doctors Without Borders, said at least 6,700 Rohingya were killed in the very first month of violence.