For the fourth day in a row, an online threat was made against an aircraft, authorities said.
The Federal Bureau of Investigation said a flight from Los Angeles International Airport to O'Hare International Airport in Chicago received an online threat early Tuesday afternoon. Like threats made earlier this week, the threat pertained to a "bomb" being on board. The FBI did not immediately identify the flight.
Passengers and luggage were screened upon arrival in Chicago and no bomb was found. More Twitter threats against other flights were made later Tuesday, with a user tweeting to Delta Air Lines, Southwest Airlines, and American Airlines saying that a bomb was aboard planes. No flight disruptions had been announced.
The user's account was quickly suspended. Two of the flights mentioned by that user landed safely as scheduled shortly after the threats were posted, others were en route, two had already landed hours earlier and another had not yet departed San Francisco.
On Saturday, two planes were escorted by fighter jets to Atlanta's airport after bomb threats were made via Twitter. A day later, a Delta Air Lines jet from Los Angeles to Orlando was diverted to Dallas/Fort Worth International Airport after a threat was made on Twitter.
On Monday, several bomb threats targeting Southwestern flights popped up on Twitter, but no flight disruptions were announced, NBC San Diego reported. Another bomb threat was made against a Southwest plane in San Diego Tuesday morning, but no passengers were aboard and police later cleared the aircraft. It wasn't clear how that threat was made.
FBI officials have expressed concern regarding the increase in online threats that now number more than a dozen overall. "All threats are taken seriously and will be investigated," The FBI said in a statement.
