Villagers in Russia's south eastern Altai region are on alert following an invasion of hungry bears. People living in a nature reserve are afraid to leave home at night after a series of attacks.

The rampage started three weeks ago when the bears came out of the woods looking for food. There were so many of them that the authorities had to impose a curfew in the area.

“At night you can’t even go out anymore. The bears are walking right along the fence!” said local resident Nikolay Tabakayev.

Everyone in the village has a story about a bear encounter. Aleksey Zyryanov’s daughter and her husband spent two days trying to fight off the raging predators.

“When he saw the bear charging at him, he tried to grab the door handle but couldn’t – the bear had knocked down the door and got inside the house,” Aleksey says.

Specialists say the invasion has been caused by a poor harvest of pine nuts and berries, the staples of a bear’s diet. But they have more than just a sweet tooth – their claws are what have the villagers really worried.

Although three animals have been killed, many more are still roaming around.

Sergey Yerofeyev, chief inspector from the Altai Nature Reserve Patrol Group, said they've spotted 15 bears, “but it’s very likely there are more than 20 animals in the area”.

Local authorities are trying to come up with ways to tackle the problem, while the villagers are staying extra vigilant.

But the Russian Ministry of Natural Resources has prohibited shooting the hungry animals on the territory of the nature reserve.

Nevertheless, the national park’s forestry officer, Sergey Varganov, says that if the bears threaten the lives of local residents, they will be fired at despite the restrictions.

For safety reasons, the local administration has temporarily stopped letting tourists onto the territory of the park.

Hungry bears threaten to eat scientists

Zoo horror: man butchered by bears in Ukraine