China on Sunday launched the second of three modules needed to complete its new Tiangong space station.

The Wentian lab module was sent into space at 2:22pm, with the Long March-5B Y3 rocket carrying the module blasting off from the Wenchang space launch site in Hainan province.

Around a quarter of an hour later, the China Manned Space Agency confirmed the success of the launch.

The 23-tonne Wentian, which means quest for the heavens, measures almost 18 metres long and more than four metres wide.

It is one of three modules forming the country's Tiangong space station, and has been designed to serve as a scientific experiment platform and a backup for the core module.

The core module, Tianhe, was launched in April last year.

The third and final module, Mengtian, is scheduled to dock in October, and Tiangong is expected to become fully operational by the end of the year.