Police said Tuesday morning they found one of two projectiles fired Monday night at Yokota Air Base in western Tokyo in what they believe was an attack by radicals opposed to the presence of the U.S. military in Japan.

The projectile was discovered near the base’s runway, police officers sent to investigate the incident said, adding that they are looking for the other projectile.

The nature of the projectile was not disclosed.

The attack is the first such guerrilla incident in Tokyo since a home being built for a former top Transport Ministry official was set on fire in February 1998.

Earlier, police found two steel pipes in the storage site of a construction company in Musashi-Murayama, about 300 meters from the air base. They are believed to have been used as launchers.

The pipes, measuring 5 cm in diameter and 50 cm long, were planted in the ground, about 1 meter apart, facing the base, police said.

Police also found what appeared to be the remains of a timing device attached to a wire at the scene.

The Metropolitan Police Department has set up an investigative headquarters at its Higashi-Yamato Police Station, suspecting the projectiles were launched by antibase radicals opposed to Japan’s hosting of the Group of Eight summit in Okinawa.

Police said they received an emergency call at around 11:30 p.m. telling them that projectiles were fired at the U.S. base. A local high school student told police of seeing in the area “a pillar of fire, which disappeared in about five minutes.”

U.S. Marine arrested

NAHA, Okinawa Pref. — The Okinawa Prefectural Government has filed a protest with U.S. military authorities over the alleged molestation of a 14-year-old girl by a U.S. Marine.

A police spokesman in Okinawa said the drunken 19-year-old soldier, whose name and hometown were withheld due to his age, entered the apartment of the junior high school girl early Monday morning and molested her while she was sleeping.

The marine, stationed at Futenma Air Station in Ginowan, central Okinawa, was arrested later that day, the spokesman said.

The prefectural government said it had lodged a protest with the U.S. military over the incident, calling for stricter discipline of its personnel and action to prevent similar crimes.

“This must not happen here again. The U.S. military must be aware of how the Okinawans feel about the U.S. military presence on Okinawa,” said an official with the prefectural government.

In a statement, Seiichi Oyakawa, chief of the governor’s secretariat, cited the September 1995 rape of a local schoolgirl by three U.S. servicemen, which fueled anti-U.S. bases sentiment among Okinawa residents.

“This is a malicious case that brings back the bitter memories of past unfortunate incidents, and I must say that the lessons have not been fully learned,” Oyakawa said.