MOSCOW, June 1 (Xinhua) -- A Mi-8 helicopter crashed overnight into a lake in northern Russia, leaving two injured and the other 16 on board missing, the Ministry of Emergency Situations said Sunday morning.
The ill-fated helicopter, which went down at Lake Munozero in Tersky district of Murmansk region, "was carrying 18 people, including five crew members," said the ministry.
"Two survived and were taken to hospital. The fate of the others is unclear. Search is under way," it added.
Some reports said that there were 19 people aboard the chopper.
Investigators pointed to equipment failure and bad weather as likely causes of the crash.
"Visibility in the crash area has been terrible since last evening -- around 100 meters with heavy fog. It is practically impossible to fly in such conditions," the Murmansk regional emergency department said.
"Rescuers have reached the crash site. The debris of the helicopter is found. A small part of them is on Lake Munozero; other pieces had obviously sunken. No more people aboard the helicopter were found yet," added the regional authorities.
Among the passengers were Deputy Governor of Murmansk Sergey Skomorokhov, Regional Minister of Natural Resources Aleksey Smirnov and Director-General of Apatit JSC Aleksey Grigoryev, according to the Itar-Tass news agency.
The regional government said that the helicopter belongs to Apatit JSC, a manufacturer of chemicals and fertilizers.
The Russian Investigative Committee had also begun a criminal inquiry into the crash on suspected breaches of air safety rules.