Two men were rushed to hospital with stab wounds after "a violent disorder" broke out at a "private party" in a casino early on Sunday morning.
It is unclear what started the scene, but the pair, aged 27 and 21, were left injured after the knife attack at Casino 36 in Wolverhampton, West Midlands.
The incident took place just before 2am on Sunday, November 14.
Now, West Midlands Police have sealed off a number of roads while forensic investigations take place.
Blue and silver police tents were erected on Summer Row towards the rear of the premises. Forensics officers placed evidence markers down and recovered two knives from the scene.
No one has been arrested and it is unclear how the incident was sparked, a spokesman for the force confirmed.
The spokesman for West Midlands Police said: "We’re investigating after two men were stabbed at Casino 36 on Temple Street, Wolverhampton just before 2am this morning (November 14).
"It is believed a disorder took place when the two men were stabbed.
"Two men, aged 27 and 21, were taken to hospital with stab wounds, where they remain this morning. Thankfully their injuries are not thought to be life-changing or life-threatening.
"Enquiries continue and anyone with information is asked to contact us via Live Chat at www.west-midlands.police.uk 8am - midnight or call 101 anytime. Crimestoppers can be called anonymously on 0800 555 111. Quote crime reference 20 / 1880311 / 21."
A resident who lives opposite the casino entrance said: "It was early morning when a lot of people started coming out of the entrance, not the normal dribs and drabs, everyone at once.
"One of them said it was a private party, it was a bit chaotic outside."
In July 2019 the operators of the casino were ordered to pay £300,000 after failing to make proper checks on money laundering and spotting problem gamblers, the Express and Star reported.
The Gambling Commission found that management at the site failed to "ensure adequate customer Enhanced Due Diligence, Source of Funds and Source of Wealth checks."
It also found that Casino 36 failed to "ensure sufficient customer interaction was taking place when customers were potentially displaying signs of suffering gambling harm."
The building is described as a Super Casino. It opened in November 2016 after a huge £7.6 million investment transformed the site of the former Rubicon Casino.
It offers 24 gaming tables, 80 slot machines, electronic roulette terminals, pool tables and a private VIP area for high stakes gaming.
