U.S. airman accused of attacking boy

A file photo of the U.S. Air Base in Kadena, Okinawa, where the airman under investigation is assigned. Tensions between Okinawan residents and the U.S. military are already high Two U.S. sailors were arrested last month over accusations they raped a local woman A U.S. airman is alleged to have broken into an apartment and hit a 13-year-old boy The alleged attack is "outrageous," the Japanese foreign minister says Tokyo (CNN) -- Compounding the American military's difficulties on the Japanese island of Okinawa, a U.S. airman is under investigation over allegations he broke into a local family's home early Friday and assaulted a teenage boy before jumping off a third-floor balcony. The incident is likely to further deepen resentment among Okinawan residents about the significant U.S. military presence on the island. The situation was already extremely delicate following the arrest last month of two U.S. sailors accused of raping a local woman. That case prompted angry protests from Japanese officials and local residents. The U.S. military responded by imposing a nighttime curfew on its thousands of troops in the country -- a restriction the airman appears to have disobeyed Friday. According to Okinawa police, the suspect is alleged to have broken into the family's apartment in the village of Yomitan around 1 a.m. Friday, hit a 13-year-old boy who was in bed and damaged a television set. The boy was left with an injury to his cheek. The airman suffered "possible broken bones and internal injuries" after jumping from the apartment's balcony and has been admitted to a military hospital on the nearby U.S. Air Force base of Kadena, U.S. military officials said. U.S. military shifting Asia focus 2008: Japanese to U.S.: Get out Japanese Foreign Minister Koichiro Gemba called the incident "outrageous," noting that it took place despite the U.S. military curfew. He said the Japanese authorities would lodge a complaint with the United States. American military officials on Okinawa, which lies south of the main Japanese islands, were trying to deal with the fallout from the situation Friday. "It is extremely regrettable when an alleged incident like this occurs," said Col. Brian McDaniel, vice commander of the 18th Wing of the U.S. Air Force, which occupies the Kadena base, the largest American military installation in the Asia-Pacific region. "We are fully cooperating with Okinawan authorities on this investigation to ensure justice is served." Maj. Christopher Anderson, the head of public affairs for the 18th Wing, said he had met with the mayor of Yomitan on Friday. "This isn't how we want our people to conduct themselves," he said of the airman's alleged behavior. He added that U.S. officials were "very concerned" about the well-being of the Japanese family who were in the apartment. Japanese and U.S authorities declined to disclose details of the airman's identity Friday, other than that he was assigned to Kadena. The issue of violent crimes by U.S. troops in Japan has divided the two countries for decades. It came to a peak in 1995 when a U.S. sailor and two U.S. Marines were convicted of raping a 12-year-old girl. Tens of thousands of Okinawans took to the streets at the time demanding that the United States leave the island. Relations between the U.S. military and the people of Okinawa have also been strained in recent months over the U.S. Marine Corps' deployment of MV-22 Osprey tilt-rotor aircraft to a base on the island. Some Okinawa residents are concerned because the Osprey has had a reputation for crashing. The Okinawan community has long been against the presence of the U.S. military, which recently announced that thousands of Marines will be moved to a base in Guam. CNN's Junko Ogura reported from Tokyo, and Jethro Mullen from Hong Kong.