A Russian Arctic archipelago has declared an emergency situation over an "invasion" of dozens of polar bears that have entered homes and public buildings.

Russia's northeastern Novaya Zemlya archipelago, which has a population of around 3,000 people, has appealed for help to tackle "a mass invasion of polar bears into inhabited areas," regional authorities said in a statement.

Polar bears are affected by global warming with melting Arctic ice forcing them to spend more time on land where they compete for food.

They are recognised as an endangered species in Russia and hunting them is banned.

Russia has air force and air defence troops based on Novaya Zemlya.

Since December, more than 50 polar bears have regularly visited the archipelago's main settlement, Belushya Guba, with some displaying "aggressive behaviour," local official Alexander Minayev said in a report to regional authorities.

This included "attacks on people and entering residential homes and public buildings," he said.

"People are scared, they are afraid to leave their homes... parents are frightened to let their children go to schools and kindergartens."