The United Nations headquarters in New York City was locked down for several hours Thursday after a man was seen pacing outside one of its main gates with what police said appeared to be a shotgun.

Police negotiators were speaking with the man, who appeared to be in his 60s, and hoped to resolve the situation peacefully, NYPD spokespeople said.

Police said there was no danger to the public. People inside U.N. headquarters were initially told to shelter in place, but were later allowed to move about the complex and come and go from other entrances. The U.N. General Assembly and Security Council were both in session Thursday.

The man was first spotted around 10:30 a.m. outside a security checkpoint on Manhattan’s 1st Avenue, police said.

Videos posted on social media showed the man pacing outside the fence that rings the complex, carrying an object, possibly a firearm, pointed at his own throat.

The gates were closed and the person didn’t appear to be trying to breach the security perimeter. Numerous police

U.N. spokesperson Stéphane Dujarric said there was “zero indication” the man was a current or former UN employee.