Fewer than 1,000 finless porpoises -- grey dolphin-like animals with a hint of a grin on their bulbous faces -- are thought to remain in and around the vast river that carves through the centre of the country.

Eight porpoises from Poyang Lake in Jiangxi province were transported in water-filled metal containers by bus to two reserves in neighbouring Hubei province in central China, the official Xinhua news agency said.

The reserves in Hubei are located in traffic-free areas of the Yangtze, the report said. It was not immediately clear how many of the porpoises would be relocated.

"Our plan is to move them into waters free of human activities, so they can flourish," said agriculture ministry official Zhao Yimin, according to Xinhua.

Rampant overfishing -- sometimes with electric charges -- as well as pollution from industry and sand-dredging ships trapping the animals in their propellers have been blamed for reducing their population, with river porpoises now even fewer in numbers than the country's iconic pandas.

"The Yangtze is full of dangers for the porpoises, and human activity is set to increase," said Cao Wenxuan of the Chinese Academy of Sciences, Xinhua reported.

"The only way to prevent the species from dying out is to place them in new reserves," Cao said.

In 2013, the WWF said that the number of finless porpoises -- known in China as "river pigs" -- had halved in six years, and warned that the species was "moving fast towards its extinction". (Yahoo. uk)