A Qatari diplomat has been released from custody after an incident on a flight from Washington to Denver.
Two F-16 jets were scrambled to intercept the United Airlines plane and escort it to land safely at Denver airport on Wednesday.
Initial reports said Mohammed al-Madadi had tried to set fire to his shoes, but officials now say no explosives were found and he had apparently been trying to smoke in a plane toilet.
Investigators have been told that Mr al-Madadi was asked about the smell of smoke in the toilet and made a joke that he had been trying to light his shoes.
He is the Qatari embassy's third secretary.