MOSCOW — Dozens of polar bears have laid siege to a small military settlement deep in the Russian Arctic, leaving residents afraid to send their children to school, or even open their front doors.

The settlement, Belushya Guba, on a finger of land stretching into the Arctic Ocean, has declared a state of emergency as the bears have attacked people, broken into homes, menaced schools and feasted at a local dump.

Scenes caught on video of polar bears that had come ashore, grunting and strolling through the 2,000-person settlement, suggested a dramatic symbol of climate change. But though the receding Arctic ice has been forcing more bears off their preferred terrain, it was unclear if the latest invasion was caused by the warming seas, Russian scientists said.

While ecologists have for years warned of the risk to polar bears, the ones roaming Belushya Guba have been safe from at least one threat. Conservation authorities turned down a request from the settlement to shoot the bears, which are protected in Russia as an endangered species.