Prime Minister Hun Sen wrote to Russian Prime Minister Dmitry Medvedev on Sunday to say he was “deeply shocked and saddened” by the crash of a Russian plane that killed 224 passengers in Egypt on Saturday.

“In this hour of great sorrow, the Government and people of Cambodia join [sic] me in extending to Your Excellency and the Government and people of the Russian Federation, particularly the families and loved ones of those who perished in the crash, our deepest sympathy and heartfelt condolences,” the letter reads.

Medvedev is scheduled to visit Cambodia later this month in what will be Russia’s highest-level visit to Cambodia yet, after Nikolay Nikiforov, its minister of communications and mass media, visited in July.

The downed plane – an Airbus A-321 operated by the Russian airline Kogalymavia – broke up over Egypt’s restive Sinai peninsula on its way to St Petersburg from the resort city of Sharm el-Sheikh.

Investigations into what brought the flight down are ongoing, though the airline yesterday claimed that it had ruled out a technical malfunction, and insisted the flight had been brought down by “external action”.