Two people were shot during an annual rally celebrating marijuana in Denver, Colorado on Saturday, the Associated Press reported.

Police said one victim was shot in the leg and one more person suffered unspecified injuries. Both were taken to a local hospital and were expected to survive.

Witnesses said they heard three gunshots around 4:40 p.m., sending the crowd of thousands scattering from Civic Center Park and the area was closed down. WUSA-TV reported that the shots were heard coming from near the amphitheater in the park, where a concert was being held.

One witness told the station that he was pushed toward the stage by people rushing to flee the scene after the shots rang out.

"I'm thankful to God to be alive," the witness said. "That many people are running to get out of some area and ducking, that's how people get killed. Why does every time of event have to end in some kind of tragedy like this? First the Boston Marathon and now this?"

Authorities said earlier in the week they expected attendance at the rally -- the first since the state legalized recreational marijuana use -- to top last year's tally of 50,000 people.

"We're aware of the events in Boston," a police spokesman Aaron Kafer told the Associated Press. "Our message to the public is that, if you see something, say something."

Update, 9:59 p.m. EST: Denver police said via Twitter that another person, listed as a "juvenile," checked into a nearby hospital after reporting being grazed by a bullet.

Update, 8:58 p.m. EST: The Denver Post reported that police are looking for two black male suspects. One was described as being about 6 feet tall and weighing around 180 pounds, wearing a gray hooded sweatshirt, black pants and a "Carolina blue" baseball cap, meaning the light blue commonly worn by the University of North Carolina's sports teams. The second suspect was described as wearing a black and white checkered shirt.

A police spokesperson said the two victims were an unidentified man and woman in their twenties and confirmed that their injuries are not life-threatening.

"It was peaceful," said one attendee, Laura Forduno. "Everybody was having fun and then you heard the shots — pow-pow-pow-pow — and everybody started to run."

The Post also posted video from the scene, which can be seen below.

Watch a report from WUSA, aired Saturday, below.