It is believed an incident inside the nightclub earlier in the night led to the brawl during which the two victims were repeatedly punched and kicked in the face and head.
The police say the attackers were aged around 18 and 19 and some of them fled the scene in a hatchback-type vehicle at around 2 am.
One of the victims is thought to have lost teeth and suffered head and neck injuries and was detained overnight in hospital.
The other man was released later yesterday morning after being treated for a broken nose.
There were a large number of people in the car park at the time and police are keen to hear from anyone who may have information about the assault.
They are asked to contact either the police headquarters or Crimestoppers on 0800 555 111.
