Chicago, Illinois – Two nights before Christmas, gunfire erupted at one of the Chicago area’s most popular shopping malls, leaving four people shot and throngs of holiday shoppers and store employees running for cover.

Shots were fired about 5:45 PM Thursday at the Oakbrook Center shopping mall.

Oak Brook police Chief James Kruger said two men apparently got into a gunfight in an outdoor corridor near the Ann Taylor and Nordstrom stores.

One of the men was wounded and taken into custody and transported to a hospital, he said. The other gunman was still being sought.

Three women who were bystanders were also hit and taken to area hospitals with non-life-threatening injuries.

After the shooting, 100 police officers were at the mall, he said, including SWAT teams, going store to store to look for the other shooter.

Some people were still in those stores hiding, the chief said at a news conference about 8:00 PM. "We believe at this time there are still many patrons that may have been in some of the stores that are in backrooms with the employees," he said.

Kruger called the shooting a "very unfortunate incident that is just completely out of character for our area. A lot of people fled."

Earlier, at 6:30, an Oak Brook dispatcher had said, "All we can say is avoid the area. Mall is on lockdown."

The outdoor mall is located at 100 Oakbrook Center in Oak Brook. Late Thursday, it was announced the mall would be open on Friday – Christmas Eve.

The wounded man, in his 30s, was shot three or four times, police said. He underwent surgery at Advocate Good Samaritan Hospital in Downers Grove, police said.

Also in custody was a companion of the gunman whom police are still seeking.

The women who were shot, two in their 40s and one in her 20s, were also being treated at Good Samaritan.

A woman in her 20s fractured her ankle trying to run away and was being treated at Elmhurst Hospital.

Police said they recovered two pistols. They hadn’t made a final determination as to how many shots were fired, but witnesses told them they heard as many as 15.

Kruger said police had increased their presence at the shopping center after a well-publicized looting incident in recent weeks, and that an officer on duty, who heard multiple shots, was able to respond immediately.

"The police department has been taking this very seriously to make sure the mall and our community are being kept safe," he said. "This is just a very unfortunate incident that is completely out of character for our area."

Alex Gay (23), who was Christmas shopping at Barnes & Noble, said everything seemed fine just before the shooting.

Gay, who was with her boyfriend, began walking past Neiman Marcus, heading to Nordstrom, when she saw people, including a security guard, start running.

"I’m shook up," said Gay, of Chicago. "It was scary. Everyone was sprinting out of the mall as sirens went over intercom saying 'Emergency. Evacuate. Seek shelter.'"

"I almost got trampled," Gay said. "I was scared the shooter was near me."

Gay said she did not hear any gunshots or see anyone with a gun. She was not injured, and as of 6:30 PM, she was on her way back downtown with her boyfriend.

"I won’t be shopping in person for a long time," Gay said. "That was the scariest thing I’ve ever had happen."

Gay said she saw ambulances and a helicopter.

Standing outside Nordstrom’s, Haxhi Mulla of Downers Grove said he had been shopping inside the department store when he heard three or four muffled sounds he took to be gunshots.

"At first, nobody knew what was going on but a lady actually told us that’s a shooter, so we all started running outside," he said.

Kellie Courtney, of Willow Springs, was in the mall’s food court with two friends when someone rushed in to say there had been a shooting. The trio huddled with others near the area reserved for employees.

"We were just hiding in the back waiting to hear something," she said later in the mall’s parking lot. "We were waiting to hear from the news or the police that it was OK to evacuate."

"It was very scary," said her friend, Justice West, of Lansing. "We were there for an hour. It was a long time."

"Tonight’s isolated incident is extremely upsetting for our shopping center community," Lindsay Kahn, a spokesperson for mall owner Brookfield Properties, said in a statement. "We are grateful to our partners at the Oak Brook Police Department for their diligence in leading this developing investigation."

Brookfield Properties, part of Toronto-based Brookfield Asset Management, also manages and operates Water Tower Place and Northbrook Court. The company acquired Chicago-based retail giant General Growth Properties in 2018.

Speaking at a news conference with the police chief, DuPage County Commissioner Peter DiCianni promised stern justice for the gunmen. "I can tell you that these offenders, speaking on behalf of our state’s attorney, will be fully prosecuted," he said. "We need to send a message that we don’t tolerate this kind of crime in our county."