A low-flying drone was blamed for spooking a horse that injured three people during a winter race in southwest Colorado.

The accident happened Saturday at a skijoring race in Silverton that features horses pulling cross-country skiers through gates and jumps.

A horse darted into the crowd near the starting line when the drone appeared, The Durango Herald reported.

The mishap occurred as the horse, rider and skier prepared to leave the starting line. The horse appeared agitated, and its handler yelled and waived at the drone to make its pilot fly it away, officials said.

Instead of bolting up the course, the horse darted into a group of at least five spectators. Several people were unable to escape its path because of a large snowbank behind them.

Two women were hospitalized with non-life-threatening injuries, and a third man suffered a bloody chin, the newspaper said.

The competition was shut down for about 30 minutes while the injured people were treated.

San Juan County Sheriff Bruce Conrad said he planned to ticket the drone pilot for flying over a crowd of people, which is illegal.

He declined to identify the drone pilot before issuing the ticket.

Event organizers said drones will no longer be allowed to fly over the event, and spectators will not be allowed at the starting line, which unlike the rest of the course has no barricades.

Many spectators seemed largely unaware of the severity of the incident.

“It’s so different,” Gus von Bolschwing of Durango said about the race that he watched at about mid-course.

The town’s public works department brought in 150 dump trucks of snow and helped build the course.

It takes about four months of planning and $20,000 in sponsorships to stage the race, event organizer Pete Maisel said.

“This is like our little Fourth of July celebration in the winter,” he said.