The death toll in China cruise ship disaster has risen to 396, state media has said, making it China's deadliest boat disaster in nearly seven decades.

Disaster teams on Saturday searched the now-upright ship for more bodies as more than 100 remained unaccounted for.

Hundreds more bodies from the cruise ship were found overnight and on Saturday, bringing the death toll to 396, Hu Kaihong, the vice director-general of the press bureau of the State Council Information Office, said at a news conference.

Just 14 people have been confirmed alive out of the 456 - mostly tourists aged over 60 - on board when the "Eastern Star" rapidly sunk on the Yangtze river in a storm on Monday.

Authorities have attributed the overturning of the cruise boat to sudden, severe winds, but also have placed the surviving captain and his first engineer under police custody.

Passengers' relatives have raised questions about whether the ship should have continued its cruise after the storm started in a section of Hubei province and despite a weather warning earlier in the evening.

The vessel was cited for safety infractions two years ago, according to a notice by the Nanjing Maritime Bureau, but no further details have been given about the state of the ship.

Information about the sinking and media access to the site have been tightly controlled, and any online criticism of the search operation quickly doused.

The Eastern Star disaster could become the country's worst since the sinking of the SS Kiangya off Shanghai in 1948, which is believed to have killed anywhere from 2,750 to nearly 4,000 people.

China's deadliest maritime disaster in recent decades was the Dashun ferry, which caught fire and capsized off Shandong province in November 1999, killing about 280.

Source: Agencies