Police are responding to a man with a firearm outside the United Nations complex on the East Side of Manhattan. Update, 1:55 p.m.: The man is now in custody. [More details below]

The NYPD says officers are attempting to engage the suspect, who is described as a man possibly in his 60s. He has reportedly been pacing outside the complex since around 11 a.m. The complex has been placed on lockdown.

Authorities are advising members of the public to avoid the area of 42nd Street and 1st Avenue, as well as the FDR Drive. The MTA has also rerouted buses.

Update: At 1:41 p.m., the police said the man was in their custody and that there was no threat to the public. However, they advised the public avoid the area for now.