King Norodom Sihamoni has sent a letter of condolence to Chinese President Xi Jinping following a recent plane crash, which killed all 132 people aboard.

In his March 22 letter, the king said: “I was distressed to learn that a China Eastern Airlines jetliner had crashed in the mountains of southern China’s Guangxi region on Monday afternoon.

“In this hour of national grief, Her Majesty Queen Mother Norodom Monineath Sihanouk, the Royal Family and the people of Cambodia join me in conveying our sorrowful condolences to Your Excellency and the families of the victims.

“We are all with the family members of the victims and believe that they will be able to overcome their deep sorrow,” his letter read.

The China Eastern Airlines Boeing 737-800 crashed while travelling at a speed of 842kph after plummeting from an altitude of nearly 9km, killing all 132 passengers and crew on March 21.

Rescuers search for the black boxes amid the wreckage of the crashed aircraft in south China’s Guangxi Zhuang Autonomous Region on Monday afternoon. CHINA.ORG FB

The airline said it had offered its deepest condolences to the families and loved ones of all the passengers and crew on board. They confirmed that the cause of the crash was still under investigation.

“We are working with our client airlines and are fully prepared to assist with the investigation,” a Boeing spokesman said in a statement.

Such an accident usually involves a number of factors, although experts have warned that the plane was flying too fast. No conclusion has yet been drawn, especially as all the required information has yet been provided, the airline said.

China Eastern Airlines has suspended the operations of all Boeing 737-800 aircraft in light of the crash.