Members of the Calgary Police Service sex crime unit are investigating an alleged Sunday morning sexual assault that occurred after a woman left a bar near Stampede Park.

According to police, at approximately 4:15 a.m., the woman left Cowboys Dance Hall in the 400 block of 12 Avenue Southeast with four unidentified men after they offered her a ride home. During the drive, at least two of the males sexually assaulted the woman.

The suspects dropped the victim off on Cougarstone Way Southwest, not the neighbourhood she lives in, and she called 911.

Emergency crews responded and the woman, whose age has not been confirmed, was transported to hospital.

Investigators are reviewing surveillance video from Cowboys in an attempt to identify the suspects and the suspect vehicle.

Anyone with information about the assault is asked to contact the Calgary Police Service, 403-266-1234, or Crime Stoppers.