A polar bear has been shot dead after it attacked a cruise ship employee on an Arctic archipelago.

The worker, a designated polar bear guard, suffered a head injury as he led tourists off the ship.

He was unresponsive when he was flown to Spitsbergen Island for medical treatment but is not in a life-threatening condition.

It is not known who shot the animal but a spokesperson for the cruise ship's operator said it was killed "in an act of self-defence."

According to Hapag Lloyd Cruises, all of its cruise ships travelling in the region are obliged to carry polar bear guards on board.

Officials said the attack had occurred when tourists on the MS Bremen landed on the most northern island in the Svalbard archipelago, between mainland Norway and the North Pole.

Tourism has increased in the area in recent years, and is at its highest during the summer months.

According to a Longyearbyen port schedule, 18 cruise ships will be docking at the port this week.

Polar bear attacks are not unheard of in Norway. Scientists think human activity and climate change may be contributing to an increase in incidents.

Polar bears are most likely to attack when they are very hungry. As rising temperatures melt sea ice, the animals are likely to be forced to live closer to human habitats and may regard people as food.

Tourist companies offering "close encounters" with polar bears may also increase the animal's confidence around human beings.

Earlier this year, a polar bear reportedly killed Aaron Gibbons, 31, as he was protecting his children in Nunavat, the most northern territory in Canada.

Local officials and his relatives said they were becoming increasingly concerned for public safety as bear sightings in the area increased.