NEW : Men in custody may have been testing security . NEW : That case led U.S. authorities to ban all but small quantities of liquids from aircraft cabins . The evidence includes bottles with phones or watches inside . They follow Chicago - to - Amsterdam routes . Dutch investigators keep lid on suspects .
NEW : Men in custody may have been testing security . NEW : The evidence includes bottles with phones or watches inside . They follow Chicago - to - Amsterdam routes . Dutch investigators keep lid on suspects .