Instagram is gearing up to take on Vine by offering a new video sharing service, according to a source familiar with the plans. The move is expected to be announced on Thursday, June 20, during a mysterious Facebook press event at its headquarters in Menlo Park, California.

Facebook sent out invites to the event last week, but strangely, they were all delivered via snail mail rather than through the usual digital means. What the company has up its sleeve for the event is a mystery at this point, but according to TechCrunch, one of its announcements will be video for Instagram.

On June 20, a source says Facebook will unveil that Instagram, its popular photo-sharing app, will begin to let people also take and share short videos. Call it the Vine effect.

TechCrunch notes, however, that they haven’t been able to confirm the information, and that it could be an intentional “blind alley” that’s being circulated in an attempt to hide what Facebook’s really keeping a secret. So take this rumor with a pinch of salt for now.

But video for Instagram is something that’s been a source of rumors for some time now — particularly since Vine became a massive success with its own six-second video sharing service. A recent report claimed that Facebook has been testing the service internally, with videos between five and ten seconds in length.

It certainly seems like a move that would make sense for Instagram. Short video sharing has really taken off recently, and after Vine came to Android earlier this month, the service has become significantly more popular than Instagram on Twitter. This could breathe new life into Facebook’s $1 billion investment, then.

• SourceTechCrunch