At least 50 people were killed and more than 400 were injured when an active shooter unleashed gunfire near Mandalay Bay late Sunday night, Fox news quoted police as saying on Monday.

One officer was killed and another is in critical condition.

A shooter, identified as 64-year-old Stephen Paddock, of Mesquite, is also dead.

The shooting broke out on the Las Vegas Strip around 10 p.m. during the Route 91 Harvest Festival.

Paddock opened fire on a crowd of more than 22,000 concert-goers from his hotel room on the 32nd floor of the Mandalay Bay, police said.