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.

The man, who appeared to be in his 60s, was taken into custody without incident at around 1:30 p.m., about three hours after police said he was first spotted outside a security checkpoint on Manhattan’s First Avenue.

During the standoff, the man held an object pointed at his own throat, possibly a firearm. The gates on the fence that rings the U.N. complex were closed, and the man didn’t appear to be trying to breach the security perimeter. 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.

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

Details including criminal charges weren’t immediately available.