An earthquake with a preliminary magnitude 6.5 struck northeastern Japan late Wednesday, the US Geological Survey said, shaking buildings in the Tokyo region and briefly shutting down train lines. There were no immediate reports of injuries or damage and no danger of a tsunami, officials said. The quake hit at 8:44 p.m. (1144 GMT) Wednesday 40 kilometers (24 miles) below the sea off the coast of Ibaraki prefecture, about 120 kilometers (70 miles) northeast of Tokyo. Japan's Meteorological Agency initially measured the quake's magnitude at 6.2, but the USGS put it at 6.5. It was the second jolt in the area in recent days. A 5.1 quake outside Tokyo on Sunday shook the capital region and injured two people, though it caused no serious damage. Japan, one of the world's most earthquake-prone countries, sits atop four tectonic plates. The last major earthquake to hit Tokyo killed some 142,000 people in 1923, and experts say the capital has a 90 percent chance of suffering a major quake in the next 50 years.