Tramcars in a coal mine [file photo]

A coal mine accident in central China's Hunan Province has killed at least 15 miners and injured three others, according to Hunan Provincial Administration of Coal Mine Safety.

The accident happened?early Thursday morning in the Nanyang township of the Leiyang city, after a tramcar carrying miners derailed in a coal mine, local authorities said. The 15 were killed instantly in the crash.

An initial probe found that the miners had violated safety rules by riding in mine cars?designed to transport coal only.

Police have taken custody of the coal mine's managers.