SOUTH BURLINGTON, Vt. (AP) — A threat aboard a United Airlines aircraft prompted a massive emergency response that shut down Vermont’s international airport for about three hours before authorities determined the plane to be safe.

The threat was made Sunday afternoon on a flight en route from Newark, New Jersey, to the Burlington International Airport, Burlington police said. After landing, the plane was taken to a separate area on the tarmac.

Authorities searched the plane and its 65 passengers with bomb-sniffing dogs, one of the passengers, State Senate President Pro Tem Phil Baruth, told WCAX-TV.

The passengers were able to deplane after sitting on the tarmac for almost two hours, Baruth said. Video from WCAX showed emergency personnel lining up the baggage on the ground in front of the aircraft before searching each piece.

Baruth said the passengers were taken into a hangar.

“They isolated us with police at both ends and they don’t know whether one of us could be a bad actor, so that doesn’t feel great,” he said.

The airport was closed for about three hours and no incoming flights were canceled, said Burlington International Airport Director of Aviation Nicolas Longo. He said that by Monday, most passengers had been reunited with their luggage. He said the airplane’s crew was able to rest overnight and depart on their regular schedule Monday morning.

Longo wouldn’t discuss the details of the investigation. He said the FBI was in charge.

Authorities did not release details on the nature of the threat, which MyNBC5 reported was found in a bathroom of the aircraft. The station said the pilot then notified air traffic control.

Law enforcement authorities found no credible threat on the aircraft.

“What we have here is a safe group of people. We have a safe plane. We have a safe airport,” said Jon Murad, acting chief of the Burlington Police Department.

Longo said the airport staff had trained for emergencies and he was pleased by the response.

“I’m just extremely proud … how this all worked out, how it played out, and very thankful for the passengers and their patience,” he said.