A Chinese cargo ship capsized on the Yangtze river near the eastern city of Nanjing early on Thursday, but casualties were unknown, state media reported.
The incident follows modern China's worst shipping disaster on June 1, when 442 people died after a cruise ship also capsized on the Yangtze but in the central province of Hubei.
In the latest incident, a cargo ship -- estimated to be in the 300 tonne range - turned over and became stuck on the riverbed in Jiangsu province, state media reported. A local radio station said on its microblog that the ship is believed to have been carrying two people.
Photos posted online showed a small group of workers in orange life jackets standing on the overturned boat, attaching a steel cable to salvage the vessel.
"There are no signs of life," Jiangsu province radio reported.
The boat was carrying the chemical sodium hydroxide - also known as lye - but no leakage into the river had been detected, Jiangsu television said.
The cruise ship accident took place much further up the Yangtze, China's longest river. Only 12 people survived when the "Eastern Star" cruise ship capsized during a storm. Reports have said the 76.5-metre-long (250 feet) and 2,200-tonne ship overturned in less than a minute.
The sinking was China's worst shipping disaster since the Communist Party came to power in 1949. In 1948, up to 4,000 people on board the SS Kiangya were killed when it sank near Shanghai.