A Russian helicopter with eight people on board crashed at sea in Norway?s Svalbard archipelago in the Arctic on Thursday. Photo: AFP file.

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 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.

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

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.