"She flew to Sochi to see her sisters, whom she hadn't seen for 15 years," he said.

A spokesman for Russia's Emergencies Ministry said the plane had vanished from radar screens at 2:15 a.m. (2215 GMT Tuesday) near Sochi, which lies close to the Georgian border.

An file photo shows an Armavia Airbus A320 passenger airliner on the tarmac at Yerevan airport. An Armenian airliner crashed into the Black Sea off the Russian coast in heavy rain on May 3, and all 113 passengers and crew on board were killed. [Reuters]

"At the moment, we have absolutely no evidence pointing to the possibility of a terrorist act on the plane," Deputy General Prosecutor Nikolai Shepel told Interfax news agency.

An Armavia official said the aircraft had initially been refused permission to land because of torrential rain, but the airport officials changed their minds.

The crash happened as the crew made a second approach.

"Our initial information is that the only cause was the weather, for example poor visibility," said Gayane Davtsian, a spokeswoman for Armenia's state aviation authority.

A day of mourning was declared in Armenia, a mountainous state of 3 million people, many of whom have relatives in southern Russia. Television stations cleared their schedules and were playing sombre music.

Airbus said it would be sending six specialists to help authorities with the crash investigation.

Attempts to pin down the cause of the crash were hampered by rain and the fact that most of the plane had sunk to the seabed. "The main parts of the plane are located at a depth of around 400 metres (1,300 feet)," Beltsov said.

The Airbus A-320, a twin-engined aircraft that seats 150 passengers, entered service in 1988.