A commuter airplane flying from Philadelphia to Houston was diverted to a Tennessee airport Monday after a threatening note was found on board, authorities said.
None of the 56 passengers aboard US Airways Flight 3441 was injured, and no bomb was immediately found, authorities said.
The regional jet landed without incident at the Tri-Cities Regional Airport in eastern Tennessee about 11:30 a.m., according to airport spokeswoman Melissa Thomas.
Transportation Security Administration spokeswoman Amy von Walter said a threatening note was found on board, and FBI, TSA, canine bomb-sniffing teams and local law enforcement were investigating. Details about the note's contents were not released.
A passenger found the note and alerted the crew, said Warren Wilkinson, a vice president for Indianapolis-based Republic Airways, which operates the express flight.
"The crew contacted the cockpit," Wilkinson said. "The cockpit notified the company, and we chose to land at the closest acceptable airport."
Passengers were taken to the airport terminal and were being interviewed by the FBI, von Walter said.
Federal authorities released the plane, which the company used Monday to fly passengers on to Houston, a spokesman for US Airways said. It wasn't known how many passengers were on board.
Also Monday, a plane carrying more than 140 people from Dallas to Chicago was diverted to the airport in Shreveport, La., after crew members reported smoke in the cockpit.
Passengers boarded a different plane and continued on to Chicago, said airport spokesman Bill Cooksey. Authorities were investigating the source of the smoke.
And in Newfoundland, an Egypt Air flight carrying more than 300 passengers from Cairo to New York made an emergency landing after smoke was detected in the cockpit.
No fire was found and no one was injured, said Kevin Aylward, CEO of Goose Bay Airport Corp.