Japanese police arrested a U.S. Marine Corps officer on Sunday on suspicion of trespassing on the southern island of Okinawa amid anger over military crimes and demands for stricter regulations for U.S. troops.

Japanese police arrested a U.S. Marine Corps officer on Sunday on suspicion of trespassing on the southern island of Okinawa amid anger over military crimes and demands for stricter regulations for U.S. troops.

The incident, the second after the U.S. military had stepped up disciplinary steps last month, immediately triggered harsh reaction from the Okinawa government.

Police said 1st Lt. Tomas Chanquet of the Marine Corps Air Station Futenma allegedly sneaked into a room through an unlocked door and slept there until he was spotted by a resident who called police.

Sunday's arrest was especially inflammatory on Okinawa, where Emperor Akihito was visiting to attend a fisheries event.

"I'm too shocked to say anything. It's utterly ridiculous and extremely regrettable," Okinawa Gov. Hirokazu Nakaima told reporters. "I must lodge a strong protest to both the Japanese and U.S. governments. They must do something more significant."

Prime Minister Yoshihiko Noda is expected to raise the issue during talks Tuesday with President Obama on the sidelines of the summit of Southeast Asian countries in Phnom Penh, Cambodia, Kyodo News Agency reported.

An alleged rape by two Navy sailors last month enraged Okinawans and reignited deep-rooted anti-base sentiment on the island, home to more than half the 52,000 U.S. troops in Japan.

The case led to a curfew on all troops in Japan, but two weeks later a U.S. airman allegedly assaulted an Okinawan teenager. Sunday's incident also raises questions over the effectiveness of the curfew and other disciplinary steps.