Make sure they are not fly eggs, or you may be due for fly strike.
These usually brush out of the fur quite easily, and are usually creamy white colour.
You might have noticed if there were any flies about (not many about this time of year, but there are a few) and they usually only lay on a rabbit that is dirty, has poo or wee stuck on fur, or is sick.
Sorry to be dramatic, but this would be serious if they are.