China has launched the Shenzhou-12 spacecraft carrying three astronauts to the Tiangong space station, which is under construction in a low Earth orbit.

This is China's first crewed mission in nearly five years and the longest ever scheduled.

Astronauts Nie Haisheng, Liu Boming and Tang Hongbo will spend three months in a module around 380 kilometres above the Earth.

The astronauts will test out technologies on Tianhe including its life-support system. 

Meanwhile, construction of the space station began in April with the launch of Tianhe, the first and largest of three modules. The station is expected to be completed by 2022.