Three Chinese astronauts working at the country's space station have returned safely to Earth, state media reported Sunday, hailing the mission as a "complete success".

The return capsule of the Shenzhou-15 spaceship touched down at a landing site in northern China's Inner Mongolia region, according to state news agency Xinhua.

Astronauts Fei Junlong, Deng Qingming and Zhang Lu emerged from the capsule in "good physical condition", Xinhua reported.

"The mission... was a complete success," it said.

Footage showed medical officials in white jumpsuits and face masks swaddling the astronauts in blue blankets and carrying them away from the arid landing site, where the copper-coloured capsule lay flanked by red flags.

The trio had spent six months at the Tiangong space station, conducting spacewalks and a variety of scientific experiments.

China last week sent three more astronauts -- including its first civilian in orbit -- to the space station as part of the successor Shenzhou-16 mission.

The world's second-largest economy has pumped billions of dollars into its military-run space programme in an effort to catch up with the United States and Russia.

Beijing aims to send a crewed mission to the Moon by 2030 and plans to build a base on the lunar surface.