A U.S. Navy sailor was sentenced Friday to two and a half years in prison for raping a Japanese tourist in Okinawa, the southern island that is home to about half of the 50,000 U.S. troops in Japan.

Justin Castellanos, 24, was sentenced Friday in district court in Naha, the capital of Okinawa, according to Japanese media reports.

The sailor took the woman to his hotel room and raped her after finding her asleep in the hallway in the early hours of March 13, Kyodo News service said, citing the ruling.

His arrest, and that of an American military contractor on charges of raping and killing a 20-year-old woman, have inflamed anti-U.S. base sentiment on Okinawa. Kenneth Shinzato, a former U.S. Marine, was arrested in May after the woman's body was found in a wooded area.

Tens of thousands of people rallied last month against the presence of U.S. military bases, many wearing black to mourn the dead woman.

A major focus of the protest was a plan agreed to by the Japanese and U.S. governments to move a Marine Corps air station to a less-populated part of Okinawa. Opponents want the base moved off the island entirely.