On Aug. 8, an Air China jetliner returned to Central Japan International Airport near Nagoya and four others were temporarily delayed at Japan's airports after receiving a bomb threat, Japanese media reported, citing the country's transport ministry and the Tokyo metropolitan police.

The five flights have all departed as police found no explosives aboard any of them.

The Chinese airline also ordered all its flights not to take-off from Japan until security is ensured.

Air China's Flight CA406, which returned to the Chubu airport (Central Japan International Airport) before 4 p.m. (07:00GMT), was heading for Chongqing via Shanghai and took off from the airport shortly past 3 p.m. (06:00GMT).

And the departure of four other flights was delayed from Japan's Narita and Fukuoka airports to carry out security check after its Tokyo office received an e-mail at around 12:50 p.m. (03:50GMT), which threatened to blast the airliner.

There were reportedly a total of 70 crew and passengers aboard the aircraft, and none of them were injured.

Photograph 1: An Air China jet sits on the tarmac at Central Japan International Airport near Nagoya, Japan, on Aug. 8, 2008. An Air China flight from central Japan turned back on Aug. 8 after the airline received a bomb threat in an email that also said the Beijing Olympic Games site would be attacked, Japanese police and media said. Photo by Reuters/Kyodo

Photograph 2: Passengers reboard an Air China jet sits at Central Japan International Airport near Nagoya, Japan, on Aug. 8, 2008. An Air China flight from central Japan turned back on Aug. 8 after the airline received a bomb threat in an email that also said the Beijing Olympic Games site would be attacked, Japanese police and media said. Photo by Reuters/Kyodo

Photograph 3: An Air China jet taxis at Central Japan International Airport near Nagoya, Japan, on Aug. 8, 2008. An Air China flight from central Japan turned back on Aug. 8 after the airline received a bomb threat in an email that also said the Beijing Olympic Games site would be attacked, Japanese police and media said. Photo by Reuters/Kyodo