OSLO: A Russian helicopter with eight people on board crashed at sea in Norway's Svalbard archipelago in the Arctic on Thursday, Norwegian rescue services said.

The fate of those on board the helicopter was not immediately known.

The aircraft went down two or three kilometres from Barentsburg, a Russian mining community in the archipelago, the rescue services said.

"We've only been informed that it went down at sea. We don't know if it was a controlled landing," an emergency services spokesman told AFP.

A Norwegian helicopter and rescue vessels were dispatched to the scene, he said, adding that no contact had been made with the chopper.

Snow conditions were reported in the region at the time of the crash.

The aircraft was a Russian Mil Mi-8 based permanently near Barentsburg.

Russia's consul general in Svalbard, Viacheslav Nikolayev, told the Interfax news agency there were five crew members and three scientists on board.

"It's a civilian helicopter that belongs to the Arktikugol company and it flies the miners between (Svalbard's main town of) Longyearbyen and Barentsburg. It's a regular flight," he said.

"We know the helicopter failed to return. But whether it crashed or not, I can't say," he said.

The helicopter was reported missing by airport authorities around 3:35 pm (1335 GMT) as it was returning from Pyramiden, another former mining community that is now a tourist site.

The aircraft was confirmed to have come down about 10 minutes later, rescue services said.

Norway was afforded sovereignty of Svalbard, located around 1,000 kilometres (620 miles) from the North Pole, under the 1920 Treaty of Paris.

Nationals of all signatory states enjoy "equal liberty of access and entry" to Svalbard and its waters.

As a result, Russia operates a coal mine in Barentsburg, a community home to several hundred Russian and Ukrainian miners.

In 2008, another Mil Mi-8 crashed near Barentsburg, killing three of its nine occupants. Yet another crash near Pyramiden of the same type of helicopter left two dead in 1991.—AFP