According to Monthly Shonen GanGan September issue, a special extra chapter of Fullmetal Alchemist manga, "Hagaren Summer Time" will be published in the next issue to be released on September 11th. It's unknown that the side story will have more than one chapter although the announcement contains tantalizing comments like "It has returned!?" "It still continues!!".
Source: Scan of GanGan
Tags:
Anime