WAUWATOSA, WIS. >> Police searched Friday evening for the suspect in a shooting at a suburban Milwaukee mall that left seven adults and a teenager injured.

Wauwatosa Police Chief Barry Weber gave no motive for the attack at the Mayfair Mall in a brief update about three hours after the 2:50 p.m. incident near an entrance to the Macy’s store. He said the extent of the eight victims’ injuries was unknown, but all were alive. He added that the shooter was “no longer at the scene” when authorities arrived.

“Preliminary statements from witnesses indicate that the shooter is a white male in his 20s or 30s,” Weber told reporters. “Investigators are working on determining the identity of that suspect.”

>> PHOTOS: 8 injured in Wisconsin mall shooting

As of 9:30 p.m., Wauwatosa police said in a tweet that authorities still had not identified or arrested the suspect. But in the latest update, the department offered its first explanation of what may have led to the shooting.

“Preliminary investigation has led us to believe that this shooting was not a random act, and was the result of an altercation,” said police, who added that the mall was now cleared and secure.

Authorities said the mall will be closed Saturday and investigators will remain there overnight.

“Our thoughts go out to our community, especially those who were injured and affected by the incident today,” Wauwatosa police said in a tweet. “Events like this shake a community, and we remain committed to protecting those who live in and visit Wauwatosa.”

Witnesses told WISN-TV that they had heard what they believed to be eight to 12 gunshots. Some people remained in the mall while police searched for a suspect. The station interviewed several people outside the mall who said they had friends sheltered inside stores while the search was ongoing.

Jill Wooley was inside Macy’s with her 79-year-old mother when they heard the series of gunshots just outside the store entrance.

“We heard the first shot fired and knew immediately it was a gunshot,” Wooley told CBS58 in Milwaukee. “We both just dropped to the floor.”

Wooley said she didn’t see anyone but the shots were “very close.” She added that they ran in the opposite direction to the basement of the store, where they then hid.

Trish Cox’s 19-year-old nephew works at Finish Line sporting goods store. She said she was worried because the store’s phone wasn’t being answered and was frantic as she waited while FBI agents cleared the mall.

An agent who wouldn’t give his name said the mall was being “methodically” cleared. Heavily armed FBI personnel were visible at the mall.

Mall operator Brookfield Properties said in a statement they were “disheartened and angered that our guests and tenants were subject to this violent incident today.” They declined further comment.

In a tweet Friday evening, Wisconsin Gov. Tony Evers noted that he’s “thinking about all the customers and workers affected by this act of violence and are grateful for the first responders who helped get people to safety. As we learn more, we offer our support for the entire Wauwatosa community as they grapple with this tragedy.”

The Mayfair Mall was the site of a February shooting in which a city police officer, Joseph Mensah, shot and killed Alvin Cole, a Black 17-year-old. Police said Cole was fleeing from police; Mensah, who is also Black, said he shot Cole because Cole pointed a gun at him. The mall was the target of sporadic protests over several months in the wake of the shooting.

The Milwaukee County district attorney declined to file charges against Mensah, but the city this week agreed to a separation agreement in which Mensah will be paid at least $130,000 to leave the force.