Fire bombs have destroyed three buses near Tokyo international airport.

Police suspect it was an attack by Leftist radicals -- the fourth incident this year.

Local landowners have opposed the airport ever since it was built twenty years ago in a rice growing area seventy kilometres outside the capital.

There have been numerous violent incidents, and the Japanese authorities keep a heavy security presence there.

The radicals are supporting local farmers who are refusing to sell their land to the airport authorities for the construction of a second runway.