Police are investigating after a violent incident at Stampede Park early Thursday morning sent three people to hospital, one of them in critical condition.

At about 12:15 a.m., police were called to the park, to an area near the midway.

Once there, they found two people suffering from what appeared to be stab wounds, along with a large crowd of people attempting to help them.

Police gained control of the scene, and had the pair, one in critical and the other in stable condition, transported to Foothills Hospital.

The third victim, found in stable condition at another area off of the Stampede grounds, was taken to Rockyview Medical Centre.

According to police, the trio was involved in a fight where knives were used.

They aren't sure yet if the victims knew each other or if alcohol was connected with the altercation.

They have also detained a group of people that they say are witnesses to what happened.

Security crews on the grounds are also trying to help police determine the nature of the incident.

According to officials on the grounds, random searches are being conducted, more than in other years, but there are no metal detectors to prevent weapons from coming onto the grounds.

“We’re extremely disappointed and dismayed in the incident last night,” said Kurt Kadatz, Director, Corporate Communications, Calgary Stampede. “We have stepped up our security detail in 2015, so at the start of the year for Stampede, we knew we were going to elevate certain aspects of our security, we’ve done that. We’ve also increased our bag checks and other security measures in the last day. So we’re stepping up our vigilance.”

The investigation is ongoing and a section of the midway was closed for the morning.

“This is a very rare occurrence here in the Stampede. I’ve been involved in policing here for about ten years and this is the only time that I can recognize that a situation of this significance has occurred,” said Staff Sergeant Robin Van Gastel, Calgary Police Service.

It was reopened shortly after noon.