Polar bears could start attacking humans more frequently due to global warming, a Russian scientist said Friday.

Polar bears are carnivores that mainly live on seals, but can also feed on birds, shellfish, rodents and walruses - anything they can catch and kill. They are more likely to hunt humans than other bears and attacks could, for instance, happen at hunting camps or weather stations.

"Sea ice [the area covered by ice in the Arctic] is decreasing, and this is the polar bear's main habitat... In a search for food, the bears could end up at coastal areas and approach villages on the sea shore," Oleg Anisimov, a professor at the State Hydrology Institute under Russia's hydrometeorology service, told a news conference.

"This presents a considerable threat for people," he said.

Anisimov said that according to different estimates, ice thickness in the Arctic has reduced by 10-40% in the last 30 years.

Scientists and climatologists have been concerned that the decrease in sea ice caused by global warming could result in the extinction of the polar bear.