Bomb threats forced two Air France flights bound for Paris to be diverted Tuesday night.
An Air France jet from Los Angeles International Airport landed in Salt Lake City, while another from Washington Dulles International Airport landed in Halifax, Nova Scotia.
The aircraft were searched after they landed and no explosives were found on either plane, police and airport officials said.
The flights were "subjects of anonymous threats received by phone after takeoff," Air France spokesperson Christophe Paumier said.
Before the jets were given the all-clear, the airline said that "authorities are carrying out complete inspections of the aircraft, the passengers and their luggage."
The FBI said later Tuesday that no evidence has been found to suggest the threats were credible.
The incidents come amid heightened fears of terrorism after the deadly attacks in Paris on Friday, which killed 129 people.
A passenger on the flight from Los Angeles, Keith Rosso, told NBC News that about two hours into the flight, as they were having a meal in business class, flight attendants hurriedly grabbed plates and announced the plane was making an emergency landing.
Buses were waiting when the plane arrived in Salt Lake City, and passengers were taken to another location, to be interviewed, Rosso said.
Air France Flight 55 from Washington Dulles had 234 people aboard, and Flight 65 from Los Angeles had 473 aboard, Paumier said. Flight 55 was a Boeing 777 and Flight 65 was an Airbus 380.
Todd Palmer, special agent for the FBI Salt Lake City field office, said Tuesday night that "law enforcement personnel have conducted intensive security checks ... and have not located any evidence which would lend credibility to the threats."
The Royal Canadian Mounted Police said it was using police dogs trained to detect explosives to sweep the plane that landed at Halifax as a precaution.
Earlier Tuesday, there was a security scare aboard a London-to-Boston British Airways flight after a woman allegedly tried to open the plane's emergency exit door mid-flight, officials said.
Massachusetts State Police said in a statement Tuesday that the passenger "was intoxicated" and there was no link to terrorism.
Russian officials confirmed Tuesday that a passenger jet that crashed in Egypt Oct. 31 was brought down by a bomb. The terror group ISIS has claimed responsibility for that crash, which killed all 224 people on board.