All passengers and crew members are believed to have died after a Russian jet plane crashed near the city of Donetsk in east Ukraine on Tuesday, said an official from the Russian Emergency Situations Ministry.

Meanwhile, the deputy head of Pulkovo Airlines, to which the crashed Tu-154 belonged, also said there was no information on survivors.

The airliner, with 160 passengers and 10 crew members aboard on a flight from Anapa in southern Russia to St. Petersburg, disappeared from radar screens when it was over Ukraine.

The jet was seen on fire on the ground, Ukrainian emergencies officials were quoted as saying by Russian news agencies.

"At 3:37 PM Moscow time (11:37 GMT) the plane sent an SOS signal and at 3:39 it disappeared from radar screens," spokeswoman for the Russian Emergency Situations Ministry Irina Andrianova said.

"Early reports say the plane crashed 45 kilometers north of Donetsk" when it was over Ukraine, she added.

According to preliminary information, the airplane crashed after it entered a zone of severe turbulence, head of the Russian Federal Air Navigation Service Alexander Neradko said.

But meanwhile, Interfax Ukraine reported that a fire had broken out on board the plane shortly before it crashed.

A fire flared up inside the aircraft as it was flying at an altitude of 10,000 meters, spokesman for the Ukranian Emergency Situations Ministry Igor Krol was quoted by Interfax Ukraine as saying.

The crew tried to make an emergency landing but failed due to the malfunction of the plane's landing gear, and the jet crashed "on its belly," Krol said.

Ukrainian rescuers have reached the crash site.

Russian President Vladimir Putin has asked Prime Minister Mikhail Fradkov to form an investigation team to find out the cause of the tragedy.

(Xinhua News Agency August 23, 2006)