Photo taken on Sept 24, 2016 shows the 500-meter Aperture Spherical Telescope (FAST) in Pingtang county, Southwest China's Guizhou province. (Photo/Xinhua)

The Civil Aviation Administration of China has adjusted air routes around the world's largest radio telescope in southwestern province of Guizhou to protect the electromagnetic environment.

The Five-hundred-meter Aperture Spherical Telescope (FAST), which was put into use in September 2016 to probe space for the faintest signs of life, is sensitive to any electromagnetic interference.

The aviation authority has set up two restricted flight zones in the area, canceled two routes, and added or adjusted three other routes.

The single-dish telescope, with a diameter of half a kilometer, is located in Dawodang depression, a natural karst basin in Pingtang, once an impoverished area in mountainous Guizhou.

Nearly 10,000 residents within five kilometers of the telescope have been relocated. Visitors should also hand in their digital devices before sightseeing.