Washington: Several people were killed on Wednesday when a sacked former employee opened fire at the Milwaukee campus of brewing giant Molson Coors, with reports of up to six dead in addition to the shooter.
"There are multiple fatalities... I believe including the shooter," Milwaukee Mayor Tom Barrett told after visiting the scene.
"It's a horrible, horrible day for the employees," he said urging residents to stay away from the area.
US media including ABC News and the local Fox affiliate reported the shooter had been fired earlier in the day from the beer giant which owns the Coors and Miller brands.
The local CBS affiliate said the shooter appeared to have stolen the nametag of another employee before returning to the office complex with a gun.
The Milwaukee Journal Sentinel said several people were killed in the rampage, in addition to the shooter. The local CBS affiliate said four people were killed as well as the shooter.
Police in the Midwestern city were to hold a press conference at 6 pm CST (0000 GMT).
They tweeted that the scene remained active -- but that there was no longer an active threat. The Chicago division of the Bureau of Alcohol, Tobacco, Firearms and Explosives was also on site.
Molson Coors said it was working with the police department, adding: "Our top priority is our employees."
The Journal Sentinel earlier quoted the husband of a brewery employee Lasonya Ragdales as saying she was informed by the company of an active shooter on the premises and was texting him while locked in a room with co-workers.