MOSCOW, June 1 (Xinhua) -- At least five people were killed when a Mi-8 helicopter crashed overnight into a lake in northern Russia, authorities said Sunday.
"Five casualties have been found," said Vladimir Markin, a spokesman of the Russian Investigative Committee, as divers have started to search for victims at Lake Munozero in Tersky district of Murmansk region.
Earlier in the day, the Ministry of Emergency Situations said 18 people, including five crew members, were aboard the ill-fated aircraft, among whom two survived with injuries while the others were missing.
Some reports put the number of people on board at 19.
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," 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.