An earthquake with a preliminary magnitude of 5.4 jolted Tokyo on Wednesday, but there were no immediate reports of injuries or damage. The focus of the quake was 40 km (25 miles) underground in Ibaraki prefecture, north of the Japanese capital, the Japan Meteorological Agency said. The magnitude of the earthquake was measured according to a technique similar to the Richter scale, but adjusted for Japan's geological characteristics. A reporter for public broadcaster NHK in Tsukuba, northeast of Tokyo, told the broadcaster: "The shaking from side to side lasted for about 20 to 30 seconds. No big objects fell, but small objects fell from a desk. There seems to be no visible damage." Earthquakes are common in Japan, one of the world's most seismically active areas. The country accounts for about 20 percent of the world's earthquakes of magnitude 6 or greater. In October 2004, an earthquake with a magnitude of 6.8 struck the Niigata region in northern Japan, killing about 40 people and injuring more than 3,000. That was the deadliest quake since a magnitude 7.3 tremor hit the city of Kobe in 1995, killing more than 6,400. --SP 2328 Local Time 2028 GMT
