Amsterdam ? Prosecutors said Thursday they found no evidence of a terrorist threat aboard a Northwest Airlines flight to India that returned to Amsterdam, and they are releasing all 12 passengers arrested after the emergency landing.

The men, all Indian nationals, had aroused suspicions on Flight NW0042 to Bombay because they had a large number of cell phones, laptops and hard drives, and refused to follow the crew’s instructions, prosecutors said.

Because of those actions, the pilot of the DC-10 radioed for help shortly after takeoff Wednesday and the plane was escorted back to Amsterdam’s Schiphol Airport by two Dutch fighter jets. The 12 were arrested after the plane landed.

U.S. air marshals on the flight also were suspicious of the men, U.S. officials and passengers said.