Eight people were feared dead after a helicopter carrying 16 people, most of them tourists, crashed in a lake on the Kamchatka peninsula in Russia's Far East on Thursday.
Staff at a nature reserve described arriving at the site in two speedboats minutes after the crash to find eight survivors who had swum up from a depth of eight or nine metres.
They said two of the survivors were badly hurt and the water temperature was no more than 5-6 degrees Celsius so they would not have survived long.
The passengers were able to escape the sinking helicopter through luggage doors that opened at the rear, the regional governor said on state television.
The eight other people on board were missing.
"The bodies of the dead are most likely at the bottom of Kurilskoe lake," Interfax news agency quoted a health source as saying.
Divers were shown on state television at the lake in heavy fog. They were unable to dive down to the wreckage of the helicopter because it was too deep, Kamchatka's governor said.
The thick fog may have caused the pilot to land on the surface of the water thinking it was land, the TASS news agency cited a police source as saying.
The Kamchatka peninsula is popular among tourists for its skiing, hiking, surfing and volcanoes. It is more than 6,000 km east of Moscow and about 2,000 km west of Alaska.
The helicopter was operated by Vityaz-Aero company and had 13 passengers and three crew, the local emergency service said.

Trump dismisses Iran's reply to peace plan, oil jumps as Hormuz closure persists
UK's Starmer promises to be bolder to try to rescue his job
Evacuation of passengers from virus-hit cruise ship to be completed on Monday
Philippine lawmakers to vote on impeachment of presidential hopeful Duterte
Six people found dead in boxcar in Texas, police say
Turkish Airlines plane evacuated due to tyre fire after landing in Kathmandu
Thailand's former PM Thaksin Shinawatra released from prison
Iran sends its response to US proposal aimed at ending the war
