An outbreak of anthrax has been registered among the livestock at Russia's southern republic of Kalmykia, a police source said Monday.

A total of five sheep and goats have died at the private farm since June 17.

"On Monday, the republic's vet lab received the results of laboratory tests, showing that the animals died of anthrax," the source said.

Forty animals and two farm workers have been vaccinated.

Anthrax most commonly infects wild mammals and domestic cattle and sheep, which ingest or inhale the spores while grazing. Humans can be affected when exposed to blood and other tissues from infected animals.

Anthrax can be highly lethal, but in some forms it responds well to antibiotic treatment and there are effective vaccines against the disease.