TOKYO (Reuters) - A small explosion was heard near a U.S. military base in Japan but there were no reports of injuries, a police spokesman said early on Tuesday.
Police searched the area near the U.S. Army’s Camp Zama base southwest of Tokyo and found two pipes about 300 yards (300 meters) from the base, the spokesman said, adding that they were investigating the incident.
In Washington, Pentagon spokesman U.S. Air Force Major David Smith said the explosion did not take place on the base itself and no injuries were reported.
He said there had been reports that flares were seen in the area of the base around the same time.
The base is about 25 miles southwest of Tokyo.
Japan’s Kyodo news agency quoted police as saying the pipes might have been used to launch a small bomb at the base.
In a similar incident in November 2002, two home made rockets were fired toward Camp Zama from near the same park.
Kyodo said the explosion was heard by a resident near the camp at about 11 p.m. (1400 GMT/9 a.m. EST) on Monday.
The United States has 50,000 troops stationed in Japan under the U.S.-Japan security alliance.
Residents have complained in the past about crime, noise and pollution associated with the bases, but the public generally supports the alliance.
Violence directed against the bases is rare and is usually believed to be the work of small radical groups whose influence is minimal.
U.S. Vice-President Dick Cheney is due to visit Japan later this month to thank it for its support in the Iraq war.
Japan sent about 550 non-combat troops to southern Iraq. That mission ended last July, but about 200 air force personnel remain in Kuwait to transport supplies to the U.S.-led coalition.
Additional reporting by Andrew Gray in Washington