There was a quick reaction and support of Japanese emergency services. “There are no indications of injuries,” Pentagon spokesman U.S. Navy Commander Bill Urban said in a statement. The cause of the explosion is still under investigation. About 500 Japanese and 300 American troops and civilians work at the depot. “We urge the U.S. to provide further information, to investigate the cause and to prevent the repetition of such incidents,” Yoshihide Suga, the government’s top spokesman, said at his morning briefing. Nothing was said about a possible terrorist atack but three explosions linked to a left-wing extremist group were reported in the vicinity of the base in April. The U.S. has about 50,000 troops stationed in Japan.