A Port Authority spokesman says 250 to 300 passengers were evacuated from Terminal 1 at the airport at about 6 p.m. Sunday.
The evacuation happened after an anonymous phone caller said there was a bomb at the airport, and at the same time someone else reported an unattended bag.
Port Authority spokesman John Kelly says police checked the bag and it was not a bomb.
The Transportation Security Administration said it was notified of the telephone threat at about 5:45 p.m. EDT and that explosive detection teams responded.
Passengers returned to the terminal after 9:00 p.m.