By Tom HaysNEW YORK -- Two fighter jets escorted a Los Angeles-to-New York American Airlines flight after three passengers' repeated trips to the bathroom aroused suspicion Sunday, the 10th anniversary of the Sept. 11 attacks, officials said. The passengers were later cleared. American Airlines spokesman Tim Smith said the plane's captain never declared a security threat and never asked for law enforcement help. "In our eyes, it's a big nothing," he said. The North American Aerospace Defense Command scrambled two F-16 jets to shadow Flight 34 until it landed safely at New York's Kennedy Airport at 4:10 p.m. Sunday, the Transportation Security Administration said in a statement. FBI spokesman J. Peter Donald said in a statement that the jets were sent to escort the flight "out of an abundance of caution." The FBI interviewed passengers and found "no nexus to terrorism," he said. A similar scenario played out on a plane headed to Detroit from Denver. Police detained three passengers at Detroit's Metropolitan Airport after the crew of the Frontier Airlines flight reported suspicious activity on board and NORAD sent two F-16 jets to shadow the flight until it landed safely, the airline and federal officials said. > > Bull or Bear? Vote in Our Poll The crew of Frontier Flight 623 reported that two people were spending "an extraordinarily long time" in a bathroom, Frontier spokesman Peter Kowalchuck said. Again, the FBI said the jets shadowed the plane "out of an abundance of caution." On the American Airlines flight, the passengers made repeated trips to the bathroom and some thought they were using hand signals to communicate, the law enforcement official said. The official was not authorized to speak publicly and spoke to The Associated Press on condition of anonymity. Two of the men were Israeli and one was Russian, the official said, adding that they were cleared and sent on their way. Initial reports said the men had locked themselves in the bathroom but the official said that turned out to be erroneous. Passenger Steven Ciobo said nothing seemed amiss until he saw police lights on the runway after the plane landed. He looked out the window while still in flight and didn't notice anything.
"To be honest none of us suspected anything," said Ciobo, who works for Australia's Parliament, adding he got up at one point for the bathroom and noticed a long line but didn't think twice and sat back down. When the plane landed, he said, the airline workers told them to remain seated and that the authorities would meet the plane. Everyone was quiet as air marshals got on board and headed for the back of the plane. "To be honest, I think it's reassuring that there was such a great response from the authorities," he said. "If there are people that are stupid enough to do those things on today of all days you wonder what's going on through their heads. But the fact that there were so many authorities there ... and that it all went so smoothly, I think they did a good job. The jets intercepted the flight about 100 miles west of New York and shadowed it until it landed, said John Cornelio, spokesman for the North American Aerospace Defense Command. He described the measure as precautionary. A "security concern" was brought to the airline's attention, the crew used "normal procedures" to assess the circumstances and the plane landed as planned, according to the airline spokesman Smith. New York has been in a heightened state of security after federal officials received a credible but uncorroborated tip of a car bomb plot on the anniversary in either New York or Washington. American Airlines is a subsidiary of AMR Corp. ( AMR - Get Report).