GURNEE, Ill. — Three people were injured in a shooting outside a Chicago-area amusement park's entrance that sent visitors scrambling for safety and prompted the park to close early, authorities said.

Officers responded about 7:50 p.m. Sunday after 911 calls reporting shots fired at Six Flags Great America, about 45 miles north of Chicago, the Gurnee Police Department said.

“The shooting ... was not a random act, and appeared to be a targeted incident that occurred outside the park,” police said in a statement posted to Facebook.

According to an initial investigation, police said a white sedan entered the parking lot and drove toward the park's front entrance. People got out of the car and shot at another person in the parking lot before driving away, police said.

Additional details about the suspects, including the number of people who fired shots, wasn't immediately released. Police were investigating.

A 17-year-old boy from Aurora, Illinois, had a thigh wound and a 19-year-old woman from Appleton, Wisconsin, had a leg wound, police said. They were taken to a hospital and their wounds were described as non-life-threatening. A third victim had a shoulder injury and declined to be taken to a hospital.

Six Flags Great America said in a statement that park security responded immediately to the shooting along with Gurnee officers. Spokeswoman Rachel Kendziora said the park closed early Sunday evening, with guests and employees leaving the site under the direction of Gurnee police.

The park reopened as scheduled Monday morning, she said.

WGN News in Chicago spoke with Laurie Walker and her daughter, Grace, who were inside the park when the shooting occurred. Walker said they were waiting in line for an attraction around 7:50 p.m. when she noticed people running.

“‘There is an active shooter, get down, get down,’” Walker said she heard someone shouting. “We didn’t know what was going on, so we get down.”

Walker and her daughter climbed two fences to get where she could call her husband. Walker told WGN she was able to leave the park a short while later.

Gurnee is in Lake County, about 5 miles south of the Wisconsin border. It's about 20 miles north of Highland Park, where seven people died in a mass shooting during a July Fourth parade.