All 217 passengers onboard Virgin Atlantic flight 138 from New York JFK to Heathrow were safely evacuated from the Airbus A330 along with the crew. One passenger refused emergency treatment for smoke inhalation.

Massachusetts state police said the fire in the passenger compartment was reported at about 8.44pm (local time) and extinguished by the crew.

“Smoke and flames were emanating from a passenger seat,” said the force.

Bomb disposal officers found a device lodged between the seat cushions which ignited.

“Preliminary investigation suggests it is a battery pack consistent in appearance with an external phone charger,” the force added.

Virgin Atlantic said it was investigating what led to smoke appearing in the cabin.

“The safety and security of our customers and crew is always our top priority and we are currently investigating to fully understand the circumstances,” said a spokesperson, cited by the Associated Press.

“We’d like to thank our customers for their patience as we work with them to provide local accommodation or to rebook alternative flights to their final destination.”