Four Ukrainians were among the 217 passengers who were killed in the Russian plane crash in central Sinai, the Ukrainian Embassy in Cairo said on Sunday.

The Saint Petersburg-bound Airbus A321 crashed in central Sinai on Saturday, killing 217 passengers and seven crew members.

In a statement, the embassy said the Ukrainian government is ready to offer all possible assistance to the relatives of the victims.

The incident is Russia's deadliest air disaster since 1985.

The Russian jet operator Kogalymavia, which is also known as Metrojet, dismissed human error reports, saying a mechanical problem could be behind the tragedy.

The plane, whose passengers were mainly Russian tourists, lost contact with radar at 6.20am CLT (Cairo local time), less than half an hour after takeoff. It was flying at an altitude of 30,000 feet.

Source: MENA