BBC Verify has examined footage of a heavily-damaged convoy in Russia’s Kursk region.
It shows many damaged Russian military tracks left in the road, some filled with injured or dead soldiers, while a few others in uniform wait at the roadside.
The convoy video was filmed around 06:00 local time, as seen from the direction and length of the shadows, and first appeared online this morning.
The video was not sent to the BBC directly, but it has been shared widely on social media and the Telegram messaging app.
The uploader of the video has been detained by Russian authorities.