Developer Blizzard has teased an announcement relating to its hit shooter Overwatch for next week. A video uploaded on Overwatch's official Twitter account on Monday (3 March) signals something about the King's Row Uprising that took place in the Overwatch universe seven years ago.

King's Row is the name of one of Overwatch's original maps, set in London. The short video classifies the mission as "confidential" adding that it will be "declassified" on 11 April.

When asked by one Twitter user if a large number of retweets would result in an early reveal, Blizzard replied: "These are classified files! Not some t-shirt design reveal. Patience, heroes."

Eager Overwatch fans are also scouring the mysterious clip for clues on Reddit.

Some eagle-eyed fans have already spotted what looks like a rotating 3D model of a possible new Tracer skin and a flyer with a QR code which reads, "Mandatory Robot Registration," which could be a reference to the Omnic Crisis in the game's lore.

The brief video also shows a few familiar ability icons of several heroes as well.

Some fans predict the announcement could be an in-lore event set on a mandatory Omnic inspection day several years back in the Overwatch universe. Others say Blizzard could be releasing a new cinematic short surrounding the event.

The strange tweet does not offer any other specifics pointing to a particular event, but Blizzard promises more details on the same will be revealed soon.

Overwatch is out now for PS4, Xbox One and PC.