An American Marine was found guilty in a military court of abusive sexual conduct of a 14-year-old Japanese girl in Okinawa, southern Japan, the military said Friday.

Staff Sgt. Tyrone L. Hadnott, 38, also was sentenced to four years in prison in his court-martial, said Master Sgt. Chuck Albrecht.

Four other charges, including rape of a child under 16, making false official statements, adultery and "kidnapping through inveigling," or trickery, were dropped, Albrecht said.

Japanese police initially apprehended Hadnott in the Feb. 10 attack, but released him after the girl dropped charges. U.S. authorities then investigated the case under the strict military justice code.

Japanese police earlier said Hadnott had admitted to investigators he forced the girl down and kissed her, but that he denied raping her.

Hadnott's Feb. 11 arrest — as well as a series of other damaging criminal accusations against American troops — inflamed popular anger at the U.S. military presence.

The incident prompted the U.S. military to severely restrict troop movements on Okinawa and elsewhere and conduct an ongoing review of its anti-sexual assault education programs and guidelines.

Japan hosts some 50,000 American troops under a security treaty. About half of them are based on the tiny, congested island of Okinawa.