A cargo ship has capsized on the Yangtze River in the eastern city of Nanjing on June 18, 2015. [Photo/chinanews.com]

Rescuers have been searching for two people, missing after a cargo ship capsized on the Yangtze River in the eastern city of Nanjing.

Authorities are also bracing for potential environmental problems as the ship was carrying 280 tons of liquid alkali.

Environmental officials have been monitoring the water at the site, but have so far detected no abnormalities.

The cargo ship itself has been towed to a shipyard in Nanjing.