A remote Russian archipelago declared a state of emergency on Saturday after an "invasion" of dozens of polar bears, that country's state news agency said.
A local official, Alexander Minayev, said that 52 polar bears were spotted between December and February near Belushya Guba, a settlement on the Novaya Zemlya archipelago in the Arctic Ocean, according to the news agency TASS.
Some of the animals have attacked people and entered residential buildings, the agency said.
"Residents, schools and kindergartens are submitting numerous oral and written complaints demanding to ensure safety in the settlement," the regional government said in a statement, according to TASS.
"The people are scared. They are frightened to leave homes and their daily routines are broken. Parents are afraid to let the children go to school or kindergarten."
The bears appeared unfazed by dogs, additional fencing around schools and patrol vehicles, TASS reported.
A team of experts would be sent to Novaya Zemlya to assess the bears' behaviour, the TASS report said, adding that the country's environmental watchdog had denied licenses allowing the killing of aggressive bears.
The TASS report did not specify a cause for the encounters.
Estimates put the worldwide population of polar bears at 26,000. The animals were listed as threatened by the U.S. Fish and Wildlife Service in 2008 amid concerns about climate change and reductions in habitat.
Though attacks on humans are rare, according to the conservation group Polar Bears International, they're expected to increase as more sea ice melts and the animals spend more time ashore.