It happened at about 00:30 on Sunday and both men were taken to hospital for treatment.
Officers are now asking anyone who saw what happened or who has information to get in touch.
They want to talk to people who were in the club or in the immediate area on Saturday night or early Sunday morning and witnessed the disturbance.

Twenty hostages and two police officers died during a 12-hour siege when Islamic militants stormed a cafe in the capital city Dhaka on Friday.
England are scheduled to play three one-day internationals and two Tests in Bangladesh.
The ECB said that "safety and security of players was always paramount".
England will play all their fixtures in Dhaka or Chittagong during their month-long visit, which begins with an ODI on 7 October.
The ECB said it will consult with the Foreign and Commonwealth Office over security in Bangladesh, and would take "appropriate steps" if advised that "the environment is not acceptably safe".

Overnight leader Rickie Fowler missed out on an automatic Ryder Cup place after carding a three-over round of 74 on Sunday to finish joint seventh.
Fowler needed to finish third and will now hope to be a wildcard pick on Davis Love's team.
Reed, on the losing team at Gleneagles in 2014, said: "I want sweet revenge, just like our whole team does."
Europe have won the competition three times in a row, and eight times in the last 10.
Reed, 26, beat fellow American Sean O'Hair and Argentina's Emiliano Grillo by a shot in New York to go top of the PGA points standings.
Scotland's Martin Laird ended two under par, while England's Olympic champion Justin Rose and Northern Ireland's Rory McIlroy finished on level par.
Reed, who represented the USA at the Presidents Cup in South Korea and at the Olympic Games in Brazil, added: "I finally get to play for the United States in the United States and I cannot wait to see how the fans are, and just have the whole crowd on our side this time."
Fowler's late slip-up saw 2015 Open champion Zach Johnson claim the final automatic spot.
1. Dustin Johnson
2. Jordan Spieth
3. Phil Mickelson
4. Patrick Reed
5. Jimmy Walker
6. Brooks Koepka
7. Brandt Snedeker
8. Zach Johnson
Captain Davis Love has four wildcard picks and will choose three after the BMW Championship on 11 September.
Love will make his final selection two weeks later after the Tour Championship, only five days before the Ryder Cup starts on 30 September.
Among those in contention for a spot, along with Fowler, are Bubba Watson, who finished ninth in the standings, and JB Holmes.
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The ticket for the Grosvenor in Norwich was bought for seven shillings and sixpence and signed at the gig by John Lennon and Ringo Starr.
It also states the band were supported at the now defunct venue on Prince of Wales Road by local band Ricky Lee and the Hucklebucks.
The ticket is being auctioned by Bonhams on 3 July.
At the time of the gig The Beatles were celebrating their first number one single From Me To You, which stayed at the top of the British singles chart for seven weeks.
Bonhams said if the ticket also contained the signatures of Paul McCartney and George Harrison, it would have been worth nearer £4,000.
Two men were seriously hurt during a disturbance at the Woodburn Miners Club in Dalkeith.
[NEXT_CONCEPT]
The England and Wales Cricket Board says it is monitoring the security situation in Bangladesh before England's tour in October.
[NEXT_CONCEPT]
Patrick Reed won his first tournament of the season at The Barclays to seal his spot on the USA Ryder Cup team.
[NEXT_CONCEPT]
A signed Beatles ticket from a concert in Norfolk in 1963 is expected to fetch up to £2,000 at auction in London.