Milwaukee police have responded Wednesday afternoon to an active shooter situation at the MillerCoors building. Authorities have not officially confirmed a shooting but they have responded to a “critical incident” and are advising the public to avoid the area.

A Molson Coors spokesman confirmed an “active situation” but didn’t provide details.

According to reports, there have been "multiple casualties," with as many as eight deaths, which includes the shooter. Local reports cited sources that the shooter was fired from the company earlier in the day and then returned with a gun.

"What has happened is there was a horrific shooting that has occurred,” Milwaukee Mayor Tom Barrett told reporters. “We’re urging all residents and people in this area to stay away from this area. ... They’re continuing their sweep to make sure there is nothing more that’s occurring. It is a horrible, horrible day for the employees here. It’s a very rough day for anyone who is close to this situation."

One employee said that she received an email warning of an active shooter near the campus’ Building 4.

Police reportedly responded to emergency calls at 2:11 p.m. local time. According to the Associated Press, the FBI and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives were also on the scene.

Local news reported “dozens” of police squad cars in the vicinity of North 4th Street and W. State Street.

Employees took shelter during the incident, while the area remained under heavy police presence.

MillerCoors employs roughly 1,400 people in Milwaukee with 600 working at the complex.

In January, MillerCoors changed its name to Molson Coors Beverage Co. The brewing company's brands include Coors, Foster's, Blue Moon, Keystone Light, Miller, Milwaukee's Best and Peroni, among many others. 

Crime Scene In this photo, police tape hangs outside of the Grand Theater in Lafayette, Louisiana, July 24, 2015. Photo: Stacy Revere/Getty Images