Two Air France flights en route to Paris from the US were diverted on Tuesday following anonymous bomb threats, and hundreds of passengers and crew were safely removed, the airline and the Federal Aviation Administration said.

Flight 65, an Airbus A-380 that departed from Los Angeles landed safely in Salt Lake City, where passengers and crew were taken off the plane and escorted into the terminal, an FAA spokesman said. The Salt Lake Tribune, citing an airport official, said the plane was carrying 497 passengers and crew.

A separate flight that left Dulles International Airport outside Washington, D.C., Flight 55, was diverted to Halifax International Airport in Nova Scotia that reported 262 passengers and crew members had safely disembarked.

In a brief statement, Air France said both flights had been the "subjects of anonymous threats received after their respective take-offs."

"As a precautionary measure and to conduct all necessary security checks, Air France, applying the safety regulations in force, decided to request the landings of both aircraft," the airline said in its statement.

"Local authorities are carrying out complete inspections of the aircraft, their passengers and their luggage," the statement said. "An investigation will be led by the authorities to identify the source of the telephone call."

Security officials have been on high alert since Islamic State militants claimed responsibility for attacks last week in Paris that killed 129 people. Russia has said the group was also responsible for the downing on October 31 of a plane returning to St. Petersburg from the Sharm al-Sheikh resort in Egypt, killing all 224 on board.

The Royal Canadian Mounted Police in Halifax said on its Twitter feed that police dogs were searching the place for the possibility of explosives.

Halifax airport spokesman Peter Spurway said the Air France Boeing 777 jet was diverted to Halifax at 10:15 p.m. eastern time/0315 GMT and was parked at the end of the airport's main runway and passengers were transferred to a secure area of the terminal building.

"Several law enforcement agencies are working in concert, following established protocol, to determine the nature of the threats which caused the aircraft to divert," FBI Special Agent Todd Palmer, of the agency's Salt Lake City division, told CNN.

Diverted passengers began sharing photos and comments via social media.

Keith Rosso, who tweeted a photo shortly after takeoff from Los Angeles, said he was "Thankful to everyone who has been working to keep everyone calm and make sure air travel is safe. Hope to be taking off again shortly."

The incidents did not appear to be causing flight delays or cancellations elsewhere.

According to data on flight tracking website flightradar24.com, flights operated by both Air France and other airlines appear to be taking off and landing normally at Charles de Gaulle Airport in Paris.

An FBI spokesman in Los Angeles declined to comment on the incidents when reached by Reuters, referring calls to the agency's Salt Lake City office. Representatives there could not immediately be reached. - Reuters