An influx of wolves preying on reindeer herds has triggered a state of emergency in the Sakha Republic, in north-eastern Russia.

Squads of hunters will pursue the wolves in a three-month "battle" from 15 January, officials say.

The most successful hunters will get bonuses. The vast, sparsely populated region is also known as Yakutia.

Experts quoted by Russian media believe a shortage of mountain hares has caused the migration of hungry wolves.