Pilots of American military aircraft flying over the western Pacific Ocean in areas frequented by the Chinese military have been targeted with lasers more than 20 times in recent months, The Wall Street Journal reports. Pentagon officials stopped short of accusing the Chinese military of involvement in the attacks, but confirmed to the Journal that the incidents occurred in and around the East China Sea, an area where Beijing has bolstered its military presence amid a long-running dispute with Japan over a chain of islands. The lasers appeared to come from fishing boats, some of which were Chinese-flagged, and from shore, officials said. Chinese personnel were accused of using military-grade lasers to target U.S. pilots in East Africa earlier this year, though in the more recent East China Sea incidents, officials said commercial-grade lasers were used. The beams from such lasers have been known to temporarily blind pilots and can cause eye damage.