An American Airlines flight carrying 179 people from Manchester, England, to Chicago was diverted to Bangor, Maine, on Friday because of security concerns, the AMR Corp subsidiary said.
It was the latest in a series of scares since police in Britain uncovered a suspected plot to blow up US-bound airliners this month. Since then security has been tightened at airports and passengers have been jittery.
The US Transportation Security Administration said it learned of "a reported threat to the aircraft while it was en route." The plane landed safely and all passengers left the plane.
Richard Hedges, an American Airlines spokesman in London, said American Airlines flight 55 from Manchester to Chicago was diverted to Bangor due to a possible security concern.
In Houston, FBI officials were questioning a man travelling from Buenos Aires on Continental Airlines Inc. flight 52 after bomb-sniffing dogs at the international arrivals area noticed something in his luggage, a TSA official said.
Officials believed he had picked up dynamite during a mining trip while he was abroad and had stored it in his suitcase.
The Continental flight flew on to Newark without the man or his luggage and was swept for explosives as a precaution. A spokesman for the Port Authority of New York and New Jersey said the incident was over and "we have an 'all clear.'"