Is it safe to delete mysql-bin files?

I have MM Replication in mysql, and I want to squeeze some free space in the box be deleting unnecessary files, I came across these mysql-bin files inside /var/db/mysql/ There are hundreds of those files like mysql-bin.000123, mysql-bin.000223 etc. I have checked the mysql replication by doing show master status and show slave status they are using some mysql-bin files at certain positions, but I guess all the other bin files are **leftovers** which will not be used anymore. In this case is it safe to delete all those mysql-bin files except the ones that replication is currently pointing at ? If it is safe to delete, then is there anything I could do to **automatically** delete those files once they are not in use ?