An Airbus A350-941 from Singapore Airlines is preparing to take off on the runway at Barcelona-El Prat Airport in Barcelona, Spain, on May 1, 2024. [AFP]

One person died and multiple people were injured aboard a Boeing 777 plane that experienced "severe turbulence" while heading from London to Singapore before it was diverted to Bangkok on Tuesday, Singapore Airlines said.

"We can confirm that there are injuries and one fatality on board the Boeing 777-300ER. There were a total of 211 passengers and 18 crew on board," the airline said in a statement on Facebook.

It did not specify how many people were injured, the extent of their injuries or whether the person who died was a passenger or crew member.

Singapore Airlines said flight SQ321 took off from London's Heathrow airport and "encountered severe turbulence en-route".

The aircraft diverted to Bangkok and landed at 3:45 pm local time (0845 GMT) Tuesday.

"We are working with the local authorities in Thailand to provide the necessary medical assistance, and sending a team to Bangkok to provide any additional assistance needed," the carrier added.

Boeing woes 

The incident adds to the number of crises facing the US plane maker.

An Alaska Airlines 737 Max Boeing flight in January had an emergency landing due to a panel on the fuselage blowing out mid-air.

The company has a late May deadline to present a plan required by the US Federal Aviation Administration, which has capped MAX production until the company shows progress on safety and quality control.

In July, the US Justice Department will make a final determination on whether to criminally prosecute Boeing.

And in September, the company faces a potential strike of 30,000 workers if it is unable to reach a contract with the International Association of Machinists and Aerospace Workers.