A flight with more than 200 passengers headed to Hong Kong from Chicago had to be diverted to Alaska in the United States, after a 22-year-old man vandalised two of the aircraft’s toilets with excrement, the BBC reported.

The United Airlines flight was forced to land in Anchorage on Thursday evening, after the man, who the police identified as a United States resident of Vietnamese origin, smeared faeces everywhere, officials said.

The man first defecated in the bathrooms, then spread the waste and also tried to flush the shirt he was wearing down a toilet, NBC Chicago reported.

He made no threats and cooperated with the authorities, BBC quoted Anchorage Airport Police spokesperson Lieutenant Joe Gamache as saying.

A spokesperson for the US Federal Bureau of Investigation, Staci Feger-Pellessier, told NBC the incident does not seem to be related to terrorism. The man, whose name has been withheld, has been taken for a psychological evaluation and is not expected to be arrested, the police told local TV station KTUU.