Moomba festivities may be under a cloud after media reports have surfaced of two armed youth gangs threatening a fight in the CBD on Saturday night.

According to Channel Seven, two gangs are planning to meet in the city for a "violent confrontation".

The fight was reportedly planned via social media app Snapchat. Credit:Courtesy of Seven News

The fight is being organised over snapchat - a video messaging app - by the notorious Apex gang, who are known for violent car thefts.

A photo of weapons, including baseball bats, knuckle dusters, machetes and knives, were sent out over the social media app which deletes images after a set period of time.