The ship named Dongfangzhixing, or “Eastern Star”, was headed from the eastern city of Nanjing to the southwestern city of Chongqing when it sank in the Jianli section of the river, in Hubei province, on Monday evening, Xinhua said.
The cause of the sinking was not immediately clear, but state broadcaster CCTV said it was an accident.
Eight people have been rescued, including the captain and chief engineer, who both said the vessel had been caught in a “cyclone”.
There were 458 people on board when the vessel sank at 9:28 pm (1328 GMT), CCTV said, including 406 Chinese passengers, five travel agency workers and 47 crew members.
According to CCTV, the vessel — which measures 76.5 metres long (250 feet) in length) — is capable of carrying up to 534 people, and was owned by a firm that operated tours in the region of the Three Gorges dam.
The Xinhua news agency said that Chinese president Xi Jinping issued an order for “all out rescue efforts” while Premier Li Keqiang ordered a work team from the State Council, China’s Cabinet, to direct search and rescue work.
Efforts have faced difficulty due to bad weather, Xinhua said.
Li, Vice Premier Ma Kai and State Councilor Yang Jing were on their way to the site, according to the agency.
Xi meanwhile ordered the provinces of Hubei and Chongqing to participate and in Xinhua’s description “properly handle the aftermath”.
China’s transport ministry and other government departments were also told to throw all available resources into the rescue effort and for the treatment of those saved, Xinhua said.
China’s Communist Party leaders are sensitive to the handling of disasters as any missteps or delays can potentially lead to criticism of their effectiveness to govern.
Xi also called for officials to heed lessons and take more effective measures to protect people’s lives, Xinhua said.
A total of 22 people, including eight foreigners, were killed when a tugboat sank on the river between the eastern cities of Jingjiang and Zhangjiagang in January.
After the January accident, the provincial government said the boat was undergoing trials without properly completing the required procedures and without first reporting the condition of the ship, as required by regulations- AFP