As many as five flights in China were affected Wednesday due to fake bomb threats, officials said.
Flights operated by China Eastern Airlines, Juneyao Airlines and Shenzhen Airlines were affected, the Xinhua news agency reported.
Juneyao Airlines received a threat call and arranged for the flight which had departed from Shanghai to return to the city so that the plane could be checked. The police found that there was no danger posed to the craft, the airline said.
The flight was finally operated using another plane after all passengers and luggage passed a safety screening, the company said.
A China Eastern Airlines flight from Lanzhou to Xi'an was also safely cleared after the airline received a similar threat.
Shenzhen Airlines received multiple threats, with a flight departing from Nanjing returning to the city after taking off. Another flight departing from Xi'an was forced to land in the city of Guilin, while a third flight departing from Beijing was delayed.
The police are investigating the incidents.