Speculation abounds over cause of China's Eastern Star ferry disaster

The Dongfangzhixing, or Eastern Star, was carrying more than 450 passengers and crew when it capsized in the Jianli section of the Yangtze River in Hubei province on Monday night.

As rescue workers continue searching for survivors, the public is seeking answers to what caused one of the mainland's worst maritime disasters.

The State Council has repeatedly reassured family members it will launch a comprehensive investigation into the accident.

Satellite data suggests the cruise ship made a 108-degree turn at about 9.20pm.

Marine equipment expert Professor Yao Zhenqiu, of Jiangsu University of Science and Technology, was quoted by news portal The Paper as saying the ship could have capsized after losing stability. A sudden U-turn can destabilise a vessel.

The Chutian Metropolis Daily reported that Eastern Star's captain was about to drop the anchor to stabilise the ship before it capsized. By then, all other ships in the vicinity had already done so amid bad weather conditions.

Both the ship's captain and its chief engineer made it to safety unharmed. They reportedly did not try to evacuate passengers. Internet users have asked why the two men were rescued first.

Also, no alarm was raised after the ship capsized, which raised the question of what the warning protocol was.

The meteorological department had issued a yellow rainstorm warning at the time of the accident.

According to the Yangtze River Administration of Navigational Affairs website, vessels that are involved in accidents after failing to obey alerts, face up to 10 days' suspension.

The captain told state-run Xinhua that the ship was hit by a tornado. The meteorological authorities said a tornado was in the vicinity at the time, but it remains unclear if it hit the ship.

News outlet Caixin reported that the Eastern Star, built in 1994, had undergone several significant modifications.