"A big wave of confusion" greeted the arrival of more than 200 passengers abroad an American Airlines flight from Barcelona because of a bomb threat at John F. Kennedy International Airport on Sunday, the busiest air travel day of the year, ABC News reported. The situation was described as a "security concern" by American Airlines.

The Boeing plane, carrying 200 passengers and nine crew members, landed in New York at 12:01 p.m. It was immediately towed to a secure area, with a bomb squad, K-9 units and emergency services being dispatched to the scene, according to the Fire Department of New York.

After being notified that an "unspecified threat" was called in, passengers were evacuated off the plane and taken to "holding buses" after nearly a half-hour on the tarmac, Robert Wolf, a passenger on the flight, tweeted.

"They told us to grab our luggage and get off," said American Airlines Flight 67 passenger Jacob Rosenberg, 37, as he waited on the tarmac to be shuttled to a gate by a Port Authority van.

The scene was described as being surrounded by more than a dozen emergency response vehicles, according to New York Daily News. "Some people were snapping photos out the windows," said Rosenberg, who was returning from Spain after a nine-day vacation with his wife, Teresa Dietrich.

"Nobody knew what was going on," Beth Henderson, 24, of Brooklyn, New York, told ABC News. "There was a gnawing worry in the pit of my stomach."

After a two-hour search with bomb-sniffing dogs, authorities found nothing dangerous on the plane or inside passenger bags. No explosives were found and the airport was cleared, the FBI told ABC News.

"Port Authority police received a phone call" about the threat, which they then characterized as a bomb threat, PA spokesman Joe Pentangelo said, declining to elaborate.

"American Airlines apologizes for any inconvenience this may have caused. However, the safety of our passengers and crew is our top priority," the Airline said in a statement.

The scare comes after a report by Britain Sunday Express speculated that five European planes were being targeted by terrorists in a Christmas attack.

The Sunday after Thanksgiving is the busiest air travel day of the year, with 2.2 million fliers, according to the Transportation Security Administration.

"It's better to be safe than sorry," said Robert Borukhov, 35, who was returning from a vacation with his wife.