Two U.S. sailors have been sentenced to prison for the rape of a Japanese woman in Okinawa, in a case that has generated strong anti-American feeling, BBC News reported.

The Naha district court handed Christopher Browning 10 years in jail and Skyler Dozierwalker nine years. In his verdict, the judge said the men were "contemptible and violent".

The incident in October 2012 exacerbated resentment of the U.S. military presence on the island and resulted in a curfew for U.S. troops.

Browning, 24, and Dozierwalker, 23, had pleaded guilty. Prosecutors had initially asked for a 12-year sentence for Browning, who also stole money from the victim.

"The ruling may seem severe, but the damage to the feelings of the victim and residents is more severe," Judge Hideyuki Suzuki was quoted by Kyodo news agency as saying.

In the wake of the attack, Okinawa's legislature passed a protest resolution calling on the U.S. to prevent crimes against local residents.

U.S. troops throughout Japan were placed under a night-time curfew, which was lifted for senior personnel and eased slightly for other personnel in February.

The U.S. bases some 26,000 troops on Okinawa under the terms of a long-standing security alliance with Japan.

But the gang-rape in 1995 of a 12-year-old girl by three U.S. service personnel led to moves to reduce the US military footprint there, amid island-wide outrage.

The U.S. says it is planning to relocate several thousand marines off Okinawa to Guam, but has linked their departure to progress on a new base in the north of the island - which many residents oppose.