A polar bear that attacked and injured a guard leading tourists off a cruise ship on an Arctic archipelago has been shot dead, according to Norwegian authorities and the cruise company.

The Joint Rescue Coordination for Northern Norway on Sunday tweeted that the attack happened when the tourists from the MS Bremen landed on the northernmost island of the Svalbard archipelago, a region between mainland Norway and the North Pole that is known for its remote terrain, glaciers, reindeer and polar bears.

The German Hapag Lloyd Cruises company, which operates the MS Bremen, told The Associated Press that two polar bear guards from their ship went on the island on Saturday and one of them "was attacked by a polar bear and injured on his head."

The polar bear was then shot dead "in an act of self-defense" by the second guard, spokeswoman Negar Etminan said.

The injured man was taken by helicopter to the town of Longyearbyen on Spitsbergen island. He was not identified and no further information was given on him.

"He was flown out, was responsive, and is currently undergoing medical treatment," Etminan said, adding that the victim was not in a life-threatening condition.

"Let's get too close to a polar bear in its natural environment and then kill it if it gets too close". Morons. https://t.co/FEPt0sYOtF — Ricky Gervais (@rickygervais) July 29, 2018

She said all cruise ships traveling in the northern region are obliged to have polar bear guards on board.

Arctic tourism to the region has risen sharply in the last few years and is now in high season. A Longyearbyen port schedule showed that 18 cruise ships will be docking at the Arctic port in the next week.

Critics lashed out at the tourists for travelling to a region with polar bears and then kill the animals when they become dangerous.

British comedian Ricky Gervais tweeted: "'Let's get too close to a polar bear in its natural environment and then kill it if it gets too close.' Morons."

Others on Twitter agreed.

"They had no right to get themselves into a situation where they needed to defend themselves," said one Twitter user.

"The Arctic is NOT a Zoo," posted another.