Denver Police Chief Robert White, front, talks while Stephanie O'Malley, manager of safety, looks on during a news conference late Saturday, Jan. 30, 2016, in Denver, after a deadly shooting and stabbing incident at The Colorado Motorcycle Expo.

(AP Photo/David Zalubowski)

Denver's police chief says one person was fatally shot and seven others were wounded when a fight broke out a motorcycle expo on Saturday.

Police Chief Robert White tells reporters that it was unclear what prompted the incident at the National Western Complex, where the Colorado Motorcycle Expo was being held this weekend. He says other events associated with the expo have been canceled.

White says investigators believe there was an exchange of gunfire. In addition to the person who was shot and killed, three others were shot. White says another person was stabbed and three others suffered injuries from a fistfight.

Denver Health's emergency department was on lockdown immediately after the incident. But that lockdown has since been lifted although Denver police continue to provide enhanced security.

Dr. Kevin McVaney of Denver Health Medical Center said six people were admitted to the hospital. He said three were in critical condition and three were stable.

McVaney did not release details about what injuries they were being treated for.

Police are interviewing a person of interest, and White says investigators believe there was more than one shooter.