New Anime To Aru Kagaku no Rail Gun Announced [Updated]

A side story of To Aru Majutsu no Index, manga "To Aru Kagaku no Rail Gun" was announced to get an anime adaptation. The notice was aired at the end of the final episode of To Aru Majutsu no Index aired on AT-X channel. The detail of the anime will be given in Dengeki Daioh May issue to be released on March 27th.

Source: Screenshot of the announcement
Source: Dengeki Daioh

According to Dengeki Daioh, the anime will start in October.

Source: Scan of Dengeki Daioh