The United Nations peacekeeping mission in Mali says, it is investigating allegations that dozens of people were massacred in the center of the country.

A video circulating on social media since Thursday shows dozens of badly-burned bodies with their eyes blindfolded and their hands bound together. Some of them appear to have holes in the back of their heads.

An official in central Mali, who asked not to be named said, the video shows the bodies of 35 men that were found on Tuesday night in the rural commune of Diabaly, an area where militant groups have been battling Malian soldiers.

The official said there were no eyewitnesses to the men’s deaths but that they are believed to be people who were arrested by the Malian army last month.