"Maybe cruise sightseeing tours shouldn't take place then polar bear guards wouldn't be needed to protect gawking tourists & polar bears would be left in peace & not shot dead merely to satisfy a photo op?"
The incident occurred during a 10-day cruise on the MS Bremen, a ship that holds up to 155 passengers.
Another posted: "So - at a time when polar bears are hungry, when there is no sea ice, you put yourself in the middle of its dinner plate and are surprised by its reaction and shoot the bear?"
The guard suffered non-life-threatening head injuries and is said to be in a stable condition.
Meanwhile fellow Twitter user Gareth Stringer commented: "Polar bear shot for being a Polar Bear".
Tourism in the area has increased dramatically in the last number of years and is now in high season.
The polar bear was shot dead after the attack prompting anger on social media
According to Hapag Lloyd Cruises, all of its cruise ships traveling in the region are obliged to have polar bear guards aboard.
The animal was shot by a second guard but a spokesperson for the German cruise ship's operator said it was killed "in an act of self-defence".
Spokeswoman Negar Etminan said: 'He was flown out, was responsive, and is now undergoing medical treatment'. "On the contrary", the statement explains, "polar bears are only observed from aboard ships, from a safe distance".
Hapag-Lloyd Cruises is very aware of its responsibility when travelling in environmentally-sensitive areas and respects all nature and wildlife.
Tourist expeditions are required to employ bear guards for the safety of the passengers. The Svalbard archipelago is a known habitat of polar bears.
Polar bears have become poster animals for climate change, with scientists identifying human-driven global warming as the biggest threat to the bears' continued existence.
Critics online, including British comedian Ricky Gervais, blamed the attack on human intrusion into polar bear territories.More news: Chelsea Superstar Agrees Personal Term With Real Madrid