CIVIC CENTER — NYPD officials are monitoring a mass shooting in Las Vegas that left at least 50 people dead, including a police officer, and injured about 406 during a concert there, officials said Monday morning.

The gunman, Stephen Paddock, perched in at 32nd floor room at the Mandalay Bay Resort and rained bullets down on some 22,000 revelers at the Route 91 Harvest Festival across the street shortly after 10 p.m., Las Vegas police said.

By the end of the mayhem, at least 50 people were killed while more than 400 were treated for injuries as the gunman lay dead, officials said.

NYPD officials don't know of any direct threats to the city but will continue to monitor the shooting.

"We don't yet know the motivation of the gunman," Police Commissioner James O'Neill said during a Monday morning press conference.

The dead included an off-duty Las Vegas police officer, his department said. Two officers responding to the gunfire were also injured.

#NYPD thoughts & prayers are with at least 20 killed, more than 100 injured in mass shooting at concert in Las Vegas. Lone gunman is down. pic.twitter.com/yMfCKISFgG — Commissioner O'Neill (@NYPDONeill) October 2, 2017

"We do know that acts of terror like this have the capability of happening anywhere in the country. It's one of the perils of living in an open, free, democratic society," O'Neill added.

In response, the NYPD has been deployed to "strategic locations" throughout the city, the commissioner said.