Amsterdam, Netherlands (CNN) -- Two men arrested at Schiphol International Airport in the Netherlands are being held on suspicion of plotting a terrorist act, Dutch authorities said Tuesday. They are Yemeni citizens who were en route to the Yemeni capital, Sanaa, from Chicago, Illinois, officials said. They were arrested Monday morning and authorities continued to question them Tuesday, Dutch prosecutors said. A U.S. law enforcement source said Monday the men may have been trying to test U.S. airport security by putting bottles attached to electronic devices in their checked baggage. But two U.S. government officials said Tuesday an initial U.S. investigation into the men shows no evidence of terrorism and no indication the men even knew each other.
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NEW: Homeland Security cautions against "jumping to any conclusions"
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An initial U.S. investigation finds no connection to terror, two officials say
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The two are Yemeni citizens, the Dutch say
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The men in custody may have been testing security, source says
Chicago
"This looks like nothing," said one of the officials, saying both men missed flights in @placeholder because of a gate change and their airline rebooked them onto the same plane.
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Another U.S. official said the @placeholder are being cautious and checking everything.
Chicago
That official said neither of the passengers was carrying items that are barred from aircraft, and federal air marshals were aboard the @placeholder-to-Amsterdam flight.