MOSCOW -- A helicopter crashed into a lake in northern Russia and 16 of the 18 people on board were missing, officials said Sunday. Two passengers, who floated to the surface still strapped into their seats, were rescued by fishermen and hospitalized for treatment of broken legs and other injuries, Rossiya state television reported.

The Mi-8 helicopter broke into three pieces after crashing into the Munozera lake in the northwestern Murmansk region on Saturday evening, emergency officials said. Divers arrived on the scene on Sunday.

The helicopter, which had a crew of five, belonged to the fertilizer company Apatit, the regional administration said on its website.

The state news agency RIA Novosti, citing unidentified sources, said that among the 13 passengers were Apatit executives and regional government officials. The report said they were believed to have been on a fishing trip.

The cause of the crash was still under investigation, but was most likely due either to technical failure of poor weather, the spokesman for the federal Investigative Committee, Vladimir Markin, said in a statement.