A total of 113 passengers and crew were killed when an Airbus A-320 belonging to Armenia's Armavia Airlines flying from the country's capital, Yerevan, crashed about six kilometers from the coast en route to an airport in Adler, which services the resort of Sochi.
The recovery operation involves more than 500 rescue workers, 27 boats and a Be-200 amphibious aircraft, the Emergencies Ministry said, adding that two more Be-200s would fly to the scene if necessary.
Yevgeny Serebryakov, a deputy emergencies minister said earlier, "The rescue operation is continuing despite poor weather."
Rescuers have recovered 47 bodies, and officials have identified two of the victims so far.
"The death toll has risen to 47 people, [and] we have been able to identify two of the victims," said Sergei Yeremin, the prosecutor for the Russian southern region of Krasnodar. He said rescue efforts would continue through the night.
The emergencies ministry has sent to the scene S-1000, Gnom and RTL deep-sea vehicles with sonar equipment that can detect objects on the seabed at a depth of up to three kilometers.
Meanwhile, Toulouse-based Airbus experts have been sent to the crash site to join investigators from Russia and Armenia in an effort to establish the cause of the tragedy.
The emergencies ministry said bad weather - heavy rain had been reported in the area - was the most probable cause of the tragedy, and prosecutors completely ruled out the possibility of a terrorist act.
A Russian air traffic expert said the crash was Russia's first incident involving an A-320, adding that the planes had appeared in Russia a little over five years ago. He said the A-320 was considered to be very safe aircraft because it had over four levels of protection.
"It is virtually impossible to 'kill' this plane," he said. "It is equipped with a full autopilot mode and the plane itself controls climbing and other flight parameters."
He said that human factors in combination with an automatic landing system failure could have caused the crash, as the crew had to reprogram the system after an air controller in Sochi had ordered the plane to land at another runway.
But Armavia Airlines said the crash was likely caused by bad weather conditions.
"Crew commander Grigory Surenovich Grigoryan was one of the [airline's] most experienced pilots and had flown Airbus airliners for years. Experts believe the crash was apparently caused not by human error but by bad weather conditions," the airline press service said.
Meanwhile, the Prosecutor General's Office has started analyzing an exchange between air traffic controllers and the plane's crew. Transport Minister Igor Levitin said he was sure the conversation would be fully reconstructed.
The Krasnodar prosecutor said the plane's flight data recorders, which could help explain the crash, had not been discovered. Divers are expected to arrive to search wreckage at a depth of 400 meters (over 1,302 feet).
"Rescue work is likely to continue throughout the night," Yeremin said. "We will continue the search until all bodies have been recovered from the sea."
