India, July 29 -- A massive operation is underway in midtown Manhattan, New York City, on Monday, after an active shooter situation developed. First visuals from the scene are out.

The incident is said to be unfolding at Blackstone building on Park Avenue between East 51st and East 52nd Streets.

The shooter is reportedly armed with an assault rifle, likely an AR-15, and hundreds of people are sheltering in place. The assailant reportedly has a bulletproof vest. The video shows massive police presence. People can be seen fleeing from the scene, while cops appeared to be moving towards the building.

Journalist Oliya Scootercaster also reported from the scene, posting on X, "Active shooter situation on Park Ave near E 52nd St in Manhattan...