Prime Minister Justin Trudeau remarked in a speech Sunday that there needs to be a full investigation into a recent mass burial site found in Ukraine.

Russia has not publicly commented after Its forces fled Izium during a major Ukrainian counter-offensive that retook most of the northeastern Kharkiv region in the past week.

The site in a forest outside Izium bore a marker saying it contained the bodies of 17 Ukrainian soldiers, but was surrounded by hundreds of individual graves marked by crosses.