Seven sailors are missing after a cargo ship from east China's Zhejiang Province capsized in wee hours Sunday near Zhoushan of the province, according to company sources.

The ship, dubbed Zheyuji No.618, belonged to Haitong Shipping Business Company of Yuhuan County of Zhejiang, the sources said.

It left Songmen Harbor of Wenling for Shanghai Saturday, carrying more than 500 tonnes of scrapped steels.

It capsized after colliding with another cargo ship, and seven men aboard fell into the sea.

Rescue work is under way, and cause of the accident is being investigated.