Investigation underway after FBI agent shoots man in Pilsen

An investigation is underway after an FBI agent opened fire and shot a man in a busy South Side neighborhood.

The shooting happened in the 1700 block of South Union Avenue in the Pilsen neighborhood, underneath the Dan Ryan during rush hour.

Multiple neighbors said they heard several shots, but it's not clear if all the gunfire came from the agent or the man he confronted.

The shooting led to a massive law enforcement response Monday evening.

CBS Skywatch was over the scene where local and federal investigators were focusing on a bike where sources say a gun was found nearby.

The agency did not say what brought the federal agent to Pilsen, but whatever led to the shooting left neighbors surprised by the rapid gunfire.

"I heard something that sounded like gunshots and I was like, 'was that gunshots?' And then I was like it couldn't be," said Joanie Faletto.

"At least 10 gunshot sounds. It's not something I'm used to hearing around here," said Ashley Myers.

Neighbors stepped outside to the overwhelming police presence.

"I can see all the blue lights flashing from all the squad cars in the apartment, just from the windows. Honestly, I was shocked with how quick there was like 10 cars," Myers said.

While neighbors would like to know more, the FBI is only confirming their agent was involved in the shooting.

"I don't even know what they would've been doing," Myers said.

The FBI is leading the investigation.

As of Monday night, there was no word on the condition of the man shot and no indication if anyone else was injured by the shooting.