Yum Update 404 Errors

I started to install update (yum update) on my fedora system and by mistake abort the operation with CTRL+C, I tried to start the update process again (yum update) but I get only this:

Loaded plugins: langpacks, presto, refresh-packagekit
[Errno 14] HTTP Error 404 – Not Found

yum clean all

was the solution for this problem