(CNN) - Eight people were injured when gunfire erupted at a suburban mall near Milwaukee on Friday, according to Wauwatosa police.
Investigators are working to identify a suspect in the shooting at Mayfair Mall, said Wauwatosa Police Chief Barry Weber at a news conference late Friday.
"Preliminary statements from witnesses indicate that the shooter is a white male in his 20s or 30s. Investigators are working on determining the identity of that suspect," he said.
Police said in a Facebook post that a preliminary investigation has led them to believe the shooting was not a random act and was "the result of an altercation."
Investigators are continuing to interview witnesses and the injured, the post said.
"The Mayfair Mall property has been cleared and is secure," the Facebook post added. "Mayfair Mall management has indicated that the mall will be closed tomorrow, Saturday, November 21. Law enforcement personnel will remain at the mall into the night processing the scene."
Weber said that the shooter was no longer at Mayfair Mall when Wauwatosa police officers arrived at the scene.
"Seven injured adults and one injured teenager were transported to the hospital by Wauwatosa Fire Department. The extent of their injuries is unknown at this time. Everybody was alive at that time, though, so there have not been any fatalities that I'm aware of," he said.
Wauwatosa Mayor Dennis McBride told CNN that "the perpetrator is at-large at this time" and about 75 police officers were on scene at Mayfair Mall one week before the start of the busy holiday season. None of the victims appeared to have injuries that were life threatening, McBride said.
A heavy police and EMT presence
The FBI in Milwaukee tweeted that agents were "currently responding to support local law enforcement tactical response to Mayfair Mall shooting incident."
A heavy police and EMT presence responded, according to footage from CNN affiliate WISN.
Police officers in tactical gear were seen entering the mall, and at least five people were carried on stretchers to ambulances, WISN reported.
Austin Seybold, 24, said he was locked down in the back room of the Finish Line store inside the mall. Seybold saw customers running past the store. Employees starting rounding up the people inside the store and "took them into the back and locked our front gate," Seybold wrote to CNN via text message from the store.
Seybold said six employees and about a dozen customers were locked in the back room for about two hours before a SWAT team escorted them out.
"It was a little frantic at first, but we managed to get everyone into the back without any hassle and everyone has remained fairly calm which is good, although we can hear what sounds like SWAT teams in the back passageways of the mall and the gravity of the situation is beginning to set in," he wrote.
Mayfair Mall posted on Facebook Friday that it was closed following the shooting.
"We are disheartened and angered that our guests and tenants were subject to this violent incident today. We are thankful for our partners at the Wauwatosa Police Department and we are cooperating with them as their investigation develops," the post read.
Wauwatosa is about seven miles northwest of Milwaukee.
The city was the site of multiple protests in October following news that Officer Joseph Mensah, who shot and killed 17-year-old Alvin Cole outside Mayfair Mall in February, would not face criminal charges.
The decision not to charge Mensah sparked protests during a monthslong wave of nationwide demonstrations over how police treat Black people.