WTF: Melbourne Also Had A Hectic, 200-Person Street Brawl Last Night

In the early hours of this morning, a hectic, 200-person brawl erupted in the Sydney CBD, that saw police called, and at least two arrests made, as the fray spilled across multiple streets. 

Whatever the fuck was in the air last night, Melbourne was also affected, with reports of another 200-person brawl, in which a clash between rival gangs shut down parts of the CBD.
ABC News report that two armed groups clashed in Federation Square, with revelers from the Moomba Festival forced to take cover.
The brawl, which is understood to have started in nearby streets before spreading to the square, took two hours for police to contain; Swanston Street was shut down, and trams were stopped for an hour.
Amateur footage shows people rushing down the stairs near Federation Square, and shows one youth, allegedly involved in the fracas, kicking down a fence at a nearby cafe.
Hon Weng Chong, who shot the footage while getting ice cream near the scene, later told ABC News:

“They would go up to the top of the stairs and somehow there was something that sparked a stampede. They just came running all the way down, it was really crazy there was like so many of them running towards us. 

All in all it was a very chaotic scene There were a lot of people at that time, and they were all quite organised in the way they were running. It was a bit scary because you didn’t know what they were going to do. It was disconcerting.”
Police used capsicum spray and batons to break up the fray, and per ABC News, “are investigating reports the gangs were vying for power.”
An eyewitness, who posted the below video, claims to have seen glass being thrown at police from a bar in Federation Square, and at least four people handcuffed.

The investigation is ongoing, and Victoria Police are looking into a number of robberies and assaults in the area that may be related.