A gunman has reportedly opened fire at a Music Festival crowd

We're investigating reports of an active shooter near/around Mandalay Bay Casino. Asking everyone to please avoid the area. #LVMPDnews

— LVMPD (@LVMPD) October 2, 2017

Aerial footage shows dozens fleeing the building, according to Daily Mail.

There have been unconfirmed reports of “multiple victims” at the open-air concert where the gunshots were heard.

Witnesses tell me people were getting shot around them #LasVegas @news3lv pic.twitter.com/xUOELxFupH

— Nathan O'Neal (@NateNews3LV) October 2, 2017

Witnesses say the shots appeared to come from a balcony on the 32nd floor of the adjoining casino at the crowd of at the Route 01 festival on the grounds below.

Witnesses report seeing “multiple injuries and fatalities”, with people being shot around them as they fled the concert show on foot.

Active shooter Las Vegas strip I'm ok locked in my room lights off windows closed. Shooter is directly across the street. Shots heard on vid pic.twitter.com/Z4mz3E3bmE

— Bryan Heifner (@HBryanBHHS) October 2, 2017

More as we get it.