A preliminary investigation found no evidence of gunfire in a terminal at New York's John F. Kennedy International Airport on Sunday, despite earlier reports of shots being heard, the airport's operator said.
No gun casings were found after a search of Terminal 8, where reports of gunshots in the departures area prompted an evacuation, the Port Authority of New York and New Jersey said in a message on social network Twitter.
"The terminal was evacuated out of an abundance of caution," the agency said. "Travellers should contact their carriers."
Video and photos posted on social media showed hundreds of people streaming out of Terminal 8, used by Air Berlin, Alaska Airlines, American Eagle, American Airlines, Finnair and other carriers.
The security measures stayed in place hours after the scare, with roadways at the airport closed and passengers milling about.
Sherwin Bryce-Pease, a correspondent with South African Broadcasting Corp based in New York, was on a Norwegian Airlines flight from Paris that landed shortly before 10 p.m. (0200 GMT).
"They told us nothing from the flight deck," he said. "Only that the earliest the gate will be available will be in an hour and 15 minutes from when we landed, an announcement greeted by huge sighs."
On Saturday, reports of gunfire sent a crowded mall in Raleigh, North Carolina, into chaos. The Crabtree Valley Mall was placed on lockdown after several shoppers reported hearing gunfire, but a search turned up no suspects or bullet casings.