NEW : Japanese defense minister says they are lodging protests with Japanese authorities . The two year - olds are accused of killing a Japanese woman on Okinawa . -- Japanese officials expressed outrage after two U.S. sailors were arrested over accusations that they raped a woman on the island of Okinawa , where the American military presence has generated long-simmering resentment . Questions over the U.S. military presence on Okinawa have boiled over in the past . The U.S. government is ` ` extremely concerned '' by the allegations , he says .
NEW : Japanese defense minister says they are lodging protests with Japanese authorities . The two year - olds are accused of killing a Japanese woman on Okinawa . Questions over the U.S. military presence on Okinawa have boiled over in the past . The U.S. government is ` ` extremely concerned '' by the allegations , he says .