Image copyright Thinkstock Image caption Fully grown monocled cobras can reach up to 2m in length

Authorities in eastern China are searching for about 50 venomous snakes after a mass escape from an unlicensed breeding farm.

About 200 monocled baby cobras escaped from the farm in Nanjing in August. So far about 150 of them have been caught or killed.

The snakelets are around 20cm (7in) in length according to Liuhe district authorities, state media Xinhua said.

Snake parts are used in a variety of traditional Chinese medicines.

Monocled cobras' venom can prove fatal if not treated. However, the baby snakes' venom is less toxic than mature snakes.

A total of 1,820 monocled cobra eggs were first brought to the Chunyi livestock farm in August, of which 1,500 hatched, Xinhua said.

But the authorities only became aware of the escape when a villager from Liuhe district discovered and killed a snake he found at home in October.

The snake farm has since been shut down.

It is not uncommon to hear of snakes escaping from farms in China. In August, 23 baby cobras escaped from a breeding farm in Sichuan.