At least 9 injured in a mass shooting in downtown Denver, police ...

At least nine people were injured in a mass shooting in downtown Denver, police said, as crowds gathered to celebrate the Nuggets’ first NBA championship.

Shots were fired during an altercation involving several people, police said, hours after the Nuggets defeated the Miami Heat at the Ball Arena less than a mile away.

Of nine people shot, three are in critical condition, and the rest are believed to have non-life-threatening injuries, police said. Officers took into custody a suspect who also had been shot, police said.

The gunfire was reported in the 2000 block of Market Street, police said, near the intersection with 20th Street. Hundreds of fans had packed the intersection and surrounding streets to celebrate the NBA title, video shows.

Police have not said whether the shooting is connected to the celebrations.

Police are conducting a “complex investigation,” they said.

The violence is among at least 291 mass shootings in the US so far this year in which four or more people were shot, excluding the shooter, according to the Gun Violence Archive.

CNN’s Lauren Mascarenhas contributed to this story.