Some of the 458 passengers aboard the Chinese ship that capsized on the Yangtze River—in what could be the country's worst maritime disaster in years—have been recovered, including the captain of the ship.

The four-deck passenger ship, Dongfangzhixing (Eastern Star), capsized around 9:30 p.m. on Monday. It is believed that the ship sank after it was caught in a cyclone in the Jianli section of the river, according to Xinhua News Agency.

It was reported by Chinese news agencies that immediately after sinking, seven people swam to shore to ask for help.

Rescue workers dispatched to the scene have reported hearing sounds from within the vessel, and are currently trying to reach the people they believe are inside the ship's cabin. So far, 12 survivors have been rescued, according to CNN.

Five bodies have also been recovered from the wreck. There remains no word about the fate of the hundreds of people still trapped inside the ship as of yet.

Chinese President Xi Jinping has ordered rescuers to spare no effort in trying to rescue those still trapped inside. Premier Li Keqiang, Vice Premier Ma Kai and State Councilor Yang Jing have also headed to the scene of the accident to oversee the rescue operations as well, according to Reuters.

The Eastern Star, operated by the Chongqing Eastern Shipping Corporation and designed to carry more than 500 people, was heading to China's Chongqing city from Nanjing, the capital of east China's Jiangsu Province, according to Reuters. The company's vice general manager, Wang Jianhua, has stated that it was the first time an accident of this magnitude has occurred in the company's history. The company has been operating since 1967.