A series of violent brawls that have erupted in the wake of a Sudanese beauty pageant in Melbourne at the weekend were predicted just days before the event took place.

At least one woman chose not to enter the Miss South Sudan Australia pageant held in Springvale on Saturday because of "boys coming drunk and starting a brawl", it has been claimed.

Up to 2000 Sudanese youths from across Australia came to Melbourne over the Easter long weekend to watch the beauty pageant and attend a series of after-parties in the following days in suburbs across Melbourne.

At least three after-parties - at Clayton, Braybrook and Ringwood - have been marred by violent brawls among drunk Sudanese youth, with one man attacked with a machete and bike chain and several others taken to hospital with stab wounds.

The latest confrontation in Ringwood last night resulted in one man being bashed unconscious.