The spokesman also did not say whether Japanese police had asked German police for cooperation in the investigation. A National Police Agency spokesman in Tokyo refused to comment on the bomb threat. On Feb. 2, three homemade rockets were fired into a cargo plane area at Tokyo's main international airport at Narita, injuring one airport worker. Two of the projectiles exploded. The ultra-leftist Revolutionary Workers Association later claimed responsibility for that attack, which came at a time when athletes, officials and spectators had been arriving at the airport on their way to Nagano.
Radicals say the government is attempting to use the airport for military purposes.
On Feb. 7, more than 300 passengers were evacuated from a Japan Airlines domestic flight after a man called the airline with a false bomb threat.