An unidentified passer-by told police that several men who appeared to be U.S. servicemen attacked the woman at about 2:30 a.m. in the parking lot in Chatan town, then fled in a vehicle, said Shoichi Shinzato, a spokesman for Okinawa state police.
The victim, who is in her 20s, told authorities she was surrounded by several foreign men and that one of them raped her, Shinzato said. She did not say what country the men were from, or whether anyone in the group had tried to stop the attack, which occurred in an area of restaurants and bars known as Â"American VillageÂ" not far from several U.S. military bases, Shinzato said.
Afterward, several U.S. Air Force personnel in uniform were questioned by police in nearby Okinawa City, where the investigation was being conducted.
Â"Right now, we are cooperating fully with the Okinawa City police department, and that's all that we can say,Â" said Masao Doi, a spokesman at Kadena Air Base in Okinawa, the largest U.S. defense facility in Asia.
In Tokyo, the U.S. Embassy also said American authorities are cooperating with the Japanese investigation and that the attack might have involved a U.S. Air Force member. However, the statement pointed out that no charges have been filed.
The assault came several hours before Prime Minister Junichiro Koizumi was to leave Japan for the United States for his first summit with President Bush. One issue they are likely to discuss is the long-standing public opposition on Okinawa to stationing 50,000 U.S. servicemen on the southern island.
Â"We can't do anything until we've seen the facts,Â" Koizumi said about the attack before his departure.
Earlier Friday, Koji Omi, the Cabinet member in charge of Okinawa, said: Â"If the reported case is true, it's greatly regrettable and we should lodge a strong protest, and necessary steps must be taken.Â"
In Okinawa, 1,000 miles southwest of Tokyo, crimes committed by U.S. soldiers against Japanese have raised public outcries in the past.
The biggest case involved the gang rape of a 12-year-old schoolgirl in 1995 by two U.S. Marines and a sailor that sparked the biggest anti-U.S. demonstrations in Japan in decades.
Last year, just before an official visit by then-President Clinton, an American soldier was arrested after entering the home of a Japanese family on Okinawa island in the middle of the night, getting into the bed of a young girl and molesting her. The U.S. military responded by imposing a drinking ban and a late-night curfew on all service members.
That case also sparked protests on the island and demands for the reduction in U.S. military bases, prompting Clinton to express regret for misconduct by American service members.
Friday's alleged attack happened just before Kadena Air Base was to begi an annual weekend festival in which the base would be opened to thousands of Japanese to promote goodwill and friendship between the community and U.S. forces.
It was to be attended by Gen. James L. Jones, the commandant of the entire U.S. Marine Corps.
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