Authorities evacuated a busy terminal at LaGuardia Airport after receiving reports of a potentially suspicious package in a shopping area, law enforcement officials said.
Officials gave the all-clear, and passengers were allowed back into the terminal about 45 minutes later.
Travelers tweeted photos of hundreds of people outside with their luggage after Central Terminal was evacuated shortly before 11 a.m. Tuesday.
New York City has been in a state of heightened alert since two bombs exploded near the finish line of Monday's Boston Marathon, killing at least three people and injuring more than 170 others.
More officers are patrolling landmark locations in the city such as the Empire State Building and World Trade Center site, but officials say there have been no reports of any specific threats.