Responding to a recent 911 call, Hopkins patrol Sgt. Darin Hill and his partner heard yelling and saw a young man crouching behind a car near a house. He was holding what appeared to be a revolver.

The police drew their guns and told him to get down on the ground. Two more young men with guns were nearby, and they too were ordered to the ground.

It turned out that the three men were having a gun battle, but that it was all in fun and with Airsoft guns, which are powered with compressed air and shoot plastic pellets. But for Hill, it was too close for comfort.

"My worry is that we will shoot someone with an Airsoft gun, or an officer will make a mistake and get shot," he said.

That has happened in other states, and Hopkins officials don't want it happening in their city. An ordinance being drafted would forbid people from having Airsoft guns out in public. To transport the guns, people would have to carry them in cases.

With warmer weather, young people -- mostly teenage boys and young men -- are playing outside with Airsoft guns, which some parents assume is OK. But the challenge of distinguishing between fake and real guns has prompted warnings from police and the Minnesota Airsoft Association, which is planning a public awareness campaign. The association was formed partly to discourage unsafe play.

'Parents should know better'

Erik Pakieser, the association's safety officer, said that with paintball parks and other private places to play Airsoft, "there's no excuse to go and play in your back yard or in a park."

"I really have to take parents to task on this," he said. "Parents should know better. ... I don't know what they're thinking, giving kids the guns as gifts and saying, 'Here, go play in the street' and thinking nothing will happen."

In most Minnesota cities, ordinances that cover a broad range of "projectile" weapons include Airsoft guns, said Dave Pecchia, executive director of the Minnesota Chiefs of Police Association.

"There seems to be a heightened awareness lately," he said. "They are more realistic looking. The only thing that really differentiates them from a real weapon is the orange tip" that is on the end of the barrel when a gun is new.

That orange tip can easily be painted over or broken off. Many Airsoft guns are so realistic looking that police departments use them in training.

"One of my biggest fears is shooting someone with a toy gun," said Lino Lakes police Sgt. Kelly McCarthy. "These are an issue for law enforcement nationwide. ... The safety issues are off the charts.

"But it's not only officers mistaking that kids have a real gun. It's that I just pointed a gun at a kid who, to a parent, is just playing in the back yard. That alone can cause divisiveness in the community."

That happened in Hopkins, where the parents of one of the young men involved in the call that Hill responded to demanded to know why their son had been confronted by armed officers. While Hill said he could tell the two other men had fake guns, the first was an Airsoft gun with "the weight, the cold steel feel and the texture of the real thing," he said later.

Hopkins Sgt. Michael Glassberg said he hopes the proposed ordinance will teach young people and parents that playing with Airsoft guns in public means risking a potentially deadly encounter with police.

The Hopkins parents were placated after a long conversation with the city's police chief.

"We have to get people to realize how close they came to a tragic situation," Glassberg said. "These decisions are made in split seconds."

Sporadic conflicts in suburbs

Last month, teenagers were arrested in Michigan for shooting Airsoft guns from a car at other vehicles. In California, five masked teenagers with Airsoft guns were detained after a report of a man with a rifle on a school roof, and in Connecticut two young boys had their Airsoft guns confiscated by police after they shot at a mail truck.

In 1997, a 15-year-old Minneapolis boy was shot by Minneapolis police after running past an officer while playing "BB gun tag" in the middle of the night. The police officer said he thought the teen was pointing a weapon at his partner.

In Twin Cities suburbs, conflicts over Airsoft guns have been sporadic. In Edina, there have been at least 22 calls in the past five years about Airsoft guns that were used in public or found in cars. In one of those cases, five juveniles were cited after one of the kids shot at a car.

Bloomington Deputy Chief Rick Hart said parents need to know that improper use of the guns can result in tragedy.

"This is where good parenting comes in," he said.

Pakieser, of the Airsoft Association, said he consulted with Minneapolis and St. Paul when those cities wrote their Airsoft ordinances a few years ago.

The group has a long and comprehensive safety guide posted on its website, and he said it plans to produce fliers that ideally would be handed out by retailers who sell the guns.

In some states, Pakieser said, Airsoft guns are illegal or their use is heavily restricted. The association opposes such bans, and to avoid problems members are urged to treat Airsoft guns exactly the same way they would treat a real firearm.

"If you use one of these in the commission of a crime, you will be charged as if it is a firearm," he said. "If you carried it on your body in the street, it's a concealed weapon. And you need to transport it as you would a real firearm: in a case, and unloaded."

He said the association has notified police about teenagers who post invitations on the group's website for Airsoft games in parks or on unauthorized private property. The group is a stickler for safety, partly to protect the sport, Pakieser said.

"I don't want this hobby to become illegal because some kid makes a mistake," he said. "And I don't want some kid getting hurt because they're not wearing eye protection or because they get on the wrong end of the police."

Mary Jane Smetanka • 612-673-7380 Twitter: @smetan