Cape Town - Two groups of men clashed at Emperors Palace Casino in Kempton Park late on Thursday in a brawl which sources say is linked to organised crime.A source who said he witnessed the fight told News24 on Friday that the intense scuffle broke out after a man linked to a notorious convict in Johannesburg was threatened by others in the casino. It was not immediately clear what this threat was about.The man then called an underworld figure with strong ties to Cape Town for backup.This figure, according to the source, then walked into the casino with about 30 other men.The man who had called for assistance, the source said, was then allegedly slapped by one of those who initially threatened him.According to the source "al hel then broke out inside (sic)".He added that chairs were overturned and bottles were smashed as fistfights broke out.Security guards from the establishment then stepped in, the source said, but were attacked by the two groups fighting each other.The two groups of men then went outside and apparently drove away.The source said some of the vehicles were bullet proof.Resolved in minutesEmperors Palace confirmed that there was an altercation late on Thursday, which the venue said was "resolved within a couple of minutes"."Please be advised in our entertainment environment we do from time to time have altercations between guests and visitors," spokesperson Julie van Wyk said."In the event of any altercation becoming aggressive, security stops the aggression and hands the matter over to the SAPS."Kempton Park police spokesperson Captain Jethro Mtshali said he was not aware of the incident, but would find out the details.RaidAt 03:30 on Friday, in another incident with links to the organised crime, the Bellville home of controversial businessman Andre Naude was raided by police.READ HERE: Cops smash their way into home of ex-bouncer boss in underworld raidItems seized included a desktop computer, several laptops and a memory stick.However, Naude said no illegal items or substances were found in his home.Naude previously ran a nightclub security business, Specialised Protection Services, with Sea Point businessman Mark Lifman.However, this company was shut down shortly after its launch as it was operating illegally.The casino brawl on Thursday night and raid on Naude's house early on Friday come as police tighten the squeeze on organised crime stretching from Cape Town to Johannesburg.An underworld battle broke out earlier this year over the nightclub security industry - a newer grouping forcefully started taking control of the bouncer trade from a more established grouping.For a detailed breakdown of underworld activities in Cape Town, see News24's showcase Underworld Unmasked here.