Authorities are responding to multiple casualties in Aurora, Ill., Friday afternoon, including several police officers, after a gunman opened fire inside a business. The suspect was apprehended, according to the City of Aurora.

"We are told that multiple people have been struck by gunfire," a spokesman for the Kane County State Attorney's Office wrote in an email Friday afternoon.

An Aurora police spokesman told The Washington Post that "multiple people ... multiple officers" were injured. The spokesperson could not confirm any fatalities. Those in the Highland-Prairie area were being asked to shelter in place.

Nancy Caal, who works at Erwin's Truck Repair near the scene of the shooting, told The Post that she heard the din of sirens as police cars and ambulances rushed to the building behind behind hers.

She and two others put the shop on lockdown when they saw heavily armed officers heading toward the adjacent Henry Pratt Warehouse.

"Nobody told us nothing," she said. "But we closed the gates and locked down the shop."

News reports of an active shooter there confirmed their fears shortly after.

"We are kind of nervous," Caal said. "It looks like something big is going on out there."

Additional details were not immediately available.