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.

FBI foils "terror plot" targeting Los Angeles
Hong Kong court finds tycoon Jimmy Lai guilty in landmark security trial
Ukraine peace talks stretch into second day at start of pivotal week for Europe
Flash floods kill at least 37 people in Morocco's Safi province
'Hero' who disarmed Bondi gunman recovering after surgery, family says
School bus accident in Colombia kills 17, injures 20
Australia plans tougher gun laws after father and son kill 15 at Bondi Beach
Police to release man detained over Brown University mass shooting
