they look "circular", there is no way to know what they are though. However, if you zoom in, you can "clearly" see that there is wide variation in the shapes and most are not circular like a tire, lots of artifacts in the image.

feel free to see tires in that image though!

I will remain unconvinced of any statement that claims they know what they are based on images like that, we need a photo not from space, or of US military grade resolution