BEIJING - A dormitory for railway workers collapsed early Wednesday in eastern China, killing nine people and leaving four missing, a state news agency said. At least 21 were injured.

The nine workers died in a hospital after the collapse in Danyang city of Jiangsu province. Twenty-one people were treated for injuries, according to the Xinhua News Agency.

Rescuers were continuing to search for the missing and police were investigating the cause of the collapse, Xinhua said.

The workers were laboring on a line between Shanghai and Nanjing, 270 kilometres to the northwest, Xinhua said. Construction workers in China often live in temporary dormitories hastily built amid rubble on the edge of work sites with little regard for safety.

Phones in the Shanghai and Nanjing railway bureaus rang unanswered, and a receptionist in the Jiangsu office said no one was available to answer questions.