NAHA, Okinawa (AP) _ Denouncing the rape of a 12-year-old Okinawa schoolgirl as ``exceptionally vicious,'' prosecutors today demanded 10-year sentences for the three U.S. servicemen accused in the assault.

In final arguments today, the prosecutors read a statement from the girl's father pleading for the harshest possible punishment for the two Marines and a Navy sailor.

``Please keep these criminals in prison until they die,'' the father appealed.

The case, in which the girl was bound, beaten and raped in the back seat of a rental car before being dumped on a remote road, has galvanized opposition to the American military presence on this small Japanese island.

The three servicemen _ Marine Pfc. Rodrico Harp of Griffin, Ga., Marine Pfc. Kendrick Ledet of Waycross, Ga., and Navy Seaman Marcus Gill of Woodville, Texas _ are being tried together in Naha District Court. They each face a charge of confinement and a charge of rape causing injury. The latter carries a sentence of three years to life in prison.

In Japan, which has judge panels instead of juries, 99 percent of criminal cases that go to trial result in convictions.

A ruling is expected in about three weeks, and sentencing would follow soon thereafter. The request of 10 years matches the stiffest sentence ever handed down by a Japanese court for the crime of rape causing injury.

Gill, 22, has confessed to the Sept. 4 rape, but Ledet, 20, and Harp, 21, say they only joined in the abduction. But in its summation today, the prosecution said Gill and Harp raped the girl and Ledet tried but was unable.

``His criminal responsibility is equally great,'' said chief prosecutor Masayuki Nomura.

Nomura repeatedly referred to what he portrayed as a chilling and calculated stalking of the girl as she shopped for school supplies in a quiet neighborhood.

``It was very well planned, and the nature of the crime was bold and exceptionally vicious,'' he said.

As the prosecutor spoke, the defendants listened quietly with heads bowed. At one point, Harp silently shook his head when Nomura asserted he had punched the girl.

In defense closing arguments, which were to follow the prosecution's, lawyer Yutaka Arakawa was expected to ask for leniency.

All three of the accused, as well as some of their family members, have apologized in court for the attack. In Japan, a show of contrition can help lighten a sentence.

The three also agreed to pay compensation to the girl and her family, but Arakawa said the girl's father refused the second installment of what was to be a $15,000 payment after hearing that the defendants would cite the payment in asking for a lesser sentence.

Okinawans have long complained of the high rate of violent crime among American service personnel _ the island hosts two-thirds of the 47,000 U.S. troops in Japan.

In a separate case today, the Naha District Court sentenced Marine Pfc. Joshua Hill, of Youngstown, Ohio, to 11 years in prison for the bludgeoning to death of an Okinawan woman last May.