Zhu Hongmei, 65, is saved from the water near the capsized ship Eastern Star, which overturned in the Jianli section of the Yangtze River in Hubei province, on Monday night. DING LIN / XINHUA

The cruise ship had set out from Nanjing, Jiangsu province, and was on its way to Chongqing in the southwest, with 46 crew members, five tour guides and 405 tourists, all from the Chinese mainland, on board, according to the Yangtze River navigation administration.

Most of the passengers were retirees. The youngest person on the passenger list authorities released was 3 years old and the oldest 83. The majority were aged between 50 and 80.

President Xi Jinping has called for an all-out rescue effort.

Premier Li, Vice-Premier Ma Kai and State Councilor Yang Jing arrived at the rescue site.

Li demanded that all government agencies, especially the Ministry of Transport, quickly contribute resources for the rescue work.

Li stressed that local governments in the area should prepare to deal with the aftermath of the disaster, and he demanded that officials conduct an investigation into the cause of the disaster. He later visited survivors in a local hospital.

Among the survivors were the ship's captain and chief engineer, who were in police custody for possible questioning.

According to Xinhua News Agency, they claimed the ship was hit by a tornado and tipped over in as little as one minute.

The China Meteorological Administration confirmed on Tuesday that there had been a tornado in the area.

Xinhua said the ship was not overloaded, and that it was equipped with enough life jackets.