A bomb threat that forced a flight from Urumqi in China's Xinjiang Uygur Autonomous Region to make an emergency landing Wednesday night was a hoax, Civil Aviation Administration of China (CAAC) said Thursday.

China Southern Airlines' flight 3912, en route from Urumqi to Guangzhou, landed safely at Zhongchuan Airport in Lanzhou, capital of the Northwest China's Gansu province, at 9:53 pm.

All the 93 passengers and 18 crew members were evacuated immediately. Among the passengers was a baby and 10 foreigners.

Police authorities in Guangzhou, where the airline company is headquartered, received an anonymous phone call at 7 pm, saying there was a bomb aboard the flight, a CAAC official said Thursday on condition of anonymity.

Security workers finished searching the aircraft by 4 am but no bomb was found, he said.

The plane had taken off from Lanzhou at 9:12 am, he added.

Public security authorities were probing the bomb hoax and would penalize the suspects in accordance with law, the official said.