A remote region in Russia has declared a state of emergency after more than 50 polar bears reportedly broke into homes and offices.

Some of the animals – forced inland by shrinking sea ice – have even attacked people on the Novaya Zemlya islands, an official said.

Hunting polar bears is banned in Russia, but authorities warn a cull may be the only answer if other means of warding them off fail.

Last year a study published in Science found polar bears are starving because climate change is melting Arctic ice, so they spend more time on land looking for food.

The animals are officially classed as “vulnerable”, with numbers falling.

Since December the military have been patrolling the streets of Belushya Guba on the islands but the animals have lost their fear of the signals used to ward them off, so more drastic measures are needed, officials said.

The village, home to about 560 people, has reported 52 bears have been spotted in two months with some of them attacking people, breaking into houses and other buildings, according to Aleksander Minaev, deputy head of the Novaya Zemlya region.

Bag a polar bear for $35,000: the new threat to the species Show all 7 1 /7 Bag a polar bear for $35,000: the new threat to the species Bag a polar bear for $35,000: the new threat to the species Hunters pay tens of thousands of dollars to kill polar bears in the Arctic GETTY IMAGES Bag a polar bear for $35,000: the new threat to the species Boyd Warner at the Pond Inlet Inuit community in Canada in 2003 Bag a polar bear for $35,000: the new threat to the species A Polar Bear sits on the Hudson Bay fresh ice next to a hole in the ice and close to the shore waiting for a seal meal PAUL J. RICHARDS/AFP/Getty Images Bag a polar bear for $35,000: the new threat to the species A Polar Bear plays with a bush on the tundra while waiting for the Hudson Bay to freeze outside Churchill, Manitoba PAUL J. RICHARDS/AFP/Getty Images Bag a polar bear for $35,000: the new threat to the species A Polar Bear sleeps on the frozen tundra with her cub waiting for the Hudson Bay to freeze overoutside Churchill, Mantioba, Canada PAUL J. RICHARDS/AFP/Getty Images Bag a polar bear for $35,000: the new threat to the species A five month old polar bear cub hunts a bird in his cage in Moscow's Zoo Yuri Tutov/AFP/Getty Images Bag a polar bear for $35,000: the new threat to the species The historical perspective: An 1879 image shows two polar bear cubs clambering over the body of their mother, who has been shot by a group of hunters Hulton Archive/Getty Images

“People are scared, afraid to leave their homes, their daily routines are being broken, and parents are unwilling to let their children go to school or kindergarten,” Mr Minaev said.

Local administration chief Vigansha Musin said more than five bears were on the grounds of a military garrison.

“I’ve been on Novaya Zemlya since 1983,” he said. “There’s never been such a mass invasion of polar bears.”

In 2016 five Russian scientists were “besieged” by polar bears for several weeks at a remote weather station on the island of Troynoy, east of Novaya Zemlya.

Russia’s remote archipelago of Novaya Zemlya (meaning New Earth), in the Arctic Ocean off northern Russia, has a population of just over 2,000 people.