TOKYO — Japanese police arrested a U.S. Marine in the alleged robbery and murder of a woman on Okinawa, officials said Sunday, the latest criminal case on the southern island where the heavy American troop presence has remained a sensitive issue.

The Okinawa prefectural police said they arrested a 20-year-old Marine stationed at the Futenma Air Station on suspicion of killing a 39-year-old local woman at a hotel in Naha, Okinawa’s capital city, and taking her wallet and backpack in the early hours of Saturday.

Kyodo News agency, citing the police, reported the woman’s body was found in her hotel room and she appeared to have been strangled to death.

Police said security camera footage showed the man believed to be the suspect entering the hotel with the victim and coming out alone. An officer arrested the suspect after spotting him walking alone on a street in Naha’s entertainment district late Saturday, Kyodo said.

“The case deals a major shock and adds fear to the Okinawans who have already been forced to live next to U.S. bases,” newly elected Okinawa Gov. Genta Koja told reporters. “It is absolutely unforgivable and we are outraged.”

“I must say, discipline and troop education are not working at all,” said Koja, referring to the U.S. military’s measures taken in response to past criminal cases.

Some 50,000 U.S. troops are deployed in Japan under a bilateral security pact, about half of them on Okinawa, whose strategic role is seen as increasingly important for the Japan-U.S. military alliance amid growing tensions with China. Japan’s southwestern shift in its military focus centers heavily on Okinawa and its nearby islands.

Okinawans have long complained about noise, pollution and crime related to U.S. bases, with crimes involving U.S. service members on Okinawa complicating ties between Japan’s central government and the Okinawa administration. The latest case comes as Prime Minister Sanae Takaichi’s cabinet pushes to further fortify its Japanese military presence on Okinawa and work more closely with the U.S. military.

“The occurrence of the heinous crime is extremely regrettable,” Takaichi said in her message on X. She said her government has strongly protested to the U.S. side and demanded maximum cooperation with the Japanese authorities in the investigation, as well as tougher discipline for U.S. service members and preventive measures.

Foreign Minister Toshimitsu Motegi summoned U.S. Ambassador to Japan George Glass to his office and conveyed “outrage,” the ministry said in a statement.

Glass, on X, expressed condolences to the victim’s family, adding that the United States is cooperating with the Japanese national and local governments.

The U.S. Marine Corps said in a statement the suspect is assigned to the III Marine Expeditionary Force on Okinawa and that it is fully cooperating with Japanese authorities. “The Marine Corps takes these allegations very seriously and expects every Marine to adhere to the highest standards of behavior.”

Futenma base, located in a densely populated area in central Okinawa, has been a sore spot for many Okinawans for decades, who demanded its relocation. Despite protests, the central government greenlit construction to relocate the base to Henoko on Okinawa’s eastern coast, though the project has faced massive delays.

A high-profile 1995 rape of a 12-year-old girl by three U.S. service members sparked massive protests against the heavy U.S. troop presence on Okinawa. The number of arrests related to U.S. service members and their families exceeded 100 last year, according to prefectural police. Repeated occurrence of sexual crimes and some of their delayed disclosures have also sparked outrage on Okinawa in recent years.