Something like this can only happen in Bihar.

As if dividing humans along caste lines wasn't enough, horses have been given castes in the state.

Horse traders at the 20-day Sonepur cattle fair near Patna look at colour, size and behaviour to classify their animals under various castes.

"The horses are identified just like humans -- as Brahmins, Kshatriyas, Vaishyas and Shudras," an official at the fair told rediff.com

White horses with wide foreheads are considered Brahmins; brown horses with keen ears and broad chests are the Kshatriyas; the Vaishyas are maroon with thin legs and long necks; and a dark brown horse of inferior quality is a Shudra.

"We decide the caste of a horse after a through check up of its colour, size, facial cut and behaviour," said horse trader Ramadhar Singh. The first criterion is colour, followed by size, he added.

"A particular horse behaves as per its caste -- horses of Brahmin caste are handsome, calm and well-behaved," said Maheshwar Pandey, a horse rider.

He said a Brahmin horse easily follows its rider's orders; a Kshatriya caste horse is strong, tough and angry; and a horse of the Shudra caste is considered ill-mannered.

The fair, which began on Sunday, is considered one of Asia's largest. It attracts cattle traders from India as well as abroad. Everything from a needle to an elephant is on sale here.

Tourists from Britain, France, the Netherlands and other countries have begun arriving for the event.