Two people were shot and a third was grazed by a bullet at a 4/20 marijuana rally in Denver on Saturday, according to the Denver Post and Denver TV station KMGH.

A man and a woman, both in their 20s, were each shot in the leg during the rally at Denver's Civic Center Park, according to the Denver Police Department's Twitter account and the Denver Post. Both victims' injuries were not considered life-threatening.

Police described the third victim as a juvenile who was grazed by a bullet and walked to a nearby hospital.

A KMGH reporter who was reporting at the rally heard four or five shots fired around 5 p.m., according to the station. When the shots were fired, crowds immediately began to scatter.

"There was just a lot of people running. Lots of people had different ideas what was happening, some people were yelling explosion, some people were yelling gunshots," Kyle, a rally attendee who only gave his first name, told KMGH. "Everybody was just sitting on the grass lying around, so it was really kind of shocking." 

Investigators don’t know what prompted the shooting, according to the Denver Post. Police are looking for two men in connection with the incident.

The annual Denver pot gathering was expected to draw 80,000 people, but it appeared to have drawn fewer than 50,000 on Saturday, according to KMGH. This was the first year the rally was held since Colorado legalized recreational marijuana use.