A strong earthquake with preliminary magnitude 6.2 hit near islands in southwestern Japan on Friday, but there was no danger of a tsunami, Japan's weather agency said. The quake struck near the island of Miyakojima, part of the Ryukyu islands chain that stretches southwest toward Taiwan, some 20 kilometers (12 miles) below the surface, the Meteorological Agency said. Coastal areas may notice some unusual movements in the ocean's surface, but there was no danger of damage, the agency said. Japan is one of the world's most earthquake-prone countries because it sits atop four tectonic plates. A magnitude 5.5 earthquake jolted northern Japan early Thusday, but there were no reports of injuries or damage.