An Air China plane en route from Beijing to the eastern city of Hangzhou turned back shortly after take-off on Nov. 20, after police in the capital received a telephoned threat, said a spokesman with Air China.

Subsequent investigations determined that the threat was a false alarm.

Flight CA1595, which took off shortly after 9 a.m., returned to the Beijing Capital International Airport (BCIA) just 10 minutes after leaving for Hangzhou, capital of Zhejiang Province.

At 9:32 a.m., local police informed the airline of an anonymous phone call threatening to take unspecified "dangerous action" against flights to Zhejiang on the morning of Nov. 20.

The airline headquarters immediately ordered CA1595 to return for another safety check and delayed the take-off of flight CA1813, which was headed for Wenzhou, a coastal city in the same province.

Subsequent security examinations found that the aircraft, passengers and cargo were safe, then the two flights took off.