Two people were shot and wounded Saturday at a “4/20” marijuana celebration in Denver, and police are searching for suspects.

The man and woman who were shot were expected to survive, Denver police spokesman Sonny Jackson told KDVR (Fox31). Police confirmed that one male and one female were shot in the leg and suffered non life-threatening injuries. Both victims are between 20 and 30 years old. It was also reported that another victim was grazed by a bullet during the shooting at Civic Center Park.

Police asked festival attendees for possible photo or video of the shootings, and had no immediate motive.

Police told KDVR that one of the suspects is believed to be a black male, about 6 feet tall and weighing about 180 pounds. He was reportedly wearing a gray hooded sweatshirt, black pants, and a Carolina baseball hat.

The second suspect was described by police as a black male who was wearing a black and white-checkered shirt, the station reported.

Witnesses said they heard three or more shots and crime tape was around the pavilion where the celebration was being held. The festive scene quickly turned to one of panic just before 5 p.m. MDT. Several thought firecrackers were being set off, then a man fell bleeding, his dog also shot.

"I saw him fall, grabbing his leg," said Travis Craig, 28, who was at the celebration. Craig said he used a belt to apply a tourniquet to the man's leg.

A crowd of marijuana smokers expected to swell to 80,000 had gathered at the park to mark the counterculture holiday known as 4/20 on the first celebration since Colorado and Washington made pot legal for recreational use. The shooting happened at about 5 p.m. and shortly after pot smokes shared hugs and joints in a mass 4:20 p.m. smoke-out. A sizable police force on motorcycles and horses had been watching the celebration. But officers didn't arrest people for smoking in public, which is still illegal. "We're aware of the events in Boston," said Denver police spokesman Aaron Kafer, who declined to give specifics about security measures being taken. "Our message to the public is that, if you see something, say something."

Nationwide, group smoke-outs were planned Saturday from New York to San Francisco. The origins of the number "420" as a code for pot are murky, but the drug's users have for decades marked the date 4/20 as a day to use pot together.