British holidaymakers returning from a sun-soaked break in Cancun, Mexico, found themselves unexpectedly stranded in the considerably chillier US state of Maine, after two passengers on their flight refused to quit smoking and sparked a brawl.

The pilot of the TUI transatlantic flight bound for London Gatwick was compelled to make an emergency landing on Tuesday, following the discovery of two passengers "smoking in the toilet."

Despite UK airlines having enforced a smoking ban for the past thirty years, the duo stubbornly continued to light up, even when the pilot threatened to land the plane if they persisted.

Irate passengers aboard the Boeing 787 Dreamliner flight informed the New York Post that the unidentified smokers seemed to be a couple, whose in-flight chaos subsequently spiralled into a fight. "They were obviously drunk, and he basically assaulted his partner," one fellow passenger revealed.

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All 267 passengers from Cancun were then subjected to an unplanned stopover in Bangor, Maine. Flight recordings disclose the pilot communicating with air traffic controllers, stating: "Cockpit is secure, and there's two passengers fighting, and the crew has pretty much gotten them under control."

Within moments, air traffic controllers had rerouted the flight and by 9.30pm, the TUI flight was grounded in Maine with airport officials escorting the pair of smokers off the aircraft.

The travel chaos only intensified for their fellow passengers, who endured an unplanned overnight stay in Bangor before catching another flight home.

They would be waiting until 3pm on Wednesday to recommence their transatlantic trip, eventually touching down safely at Gatwick later the same day.

The two troublemakers who sparked the chaos dodged any charges by US Customs and Border Protection officials, who resolved to send them back on separate flights.

An official from the border agency commented: "This incident involved a foreign-to-foreign flight that was diverted due to an in-flight altercation between two passengers.

"Upon arrival, CBP officers removed both individuals from the aircraft. Although no criminal charges were filed, CBP processed the two subjects for expedited removal."