TOKYO, Muharram 29, 1436, Nov 22, 2014, SPA -- A strong earthquake struck a mountainous area of central Japan on Saturday night, causing at least one building to collapse and injuring several people, according to Japanese media reports. No tsunami warning was issued, AP reported. The magnitude-6.8 earthquake struck near Nagano city at 10:08 p.m. (1308 GMT) at a depth of 10 kilometers (6 miles), the Japan Meteorological Agency said. The U.S. Geological Survey measured the quake's magnitude at 6.2. Since the quake occurred inland, there was no possibility of a tsunami. One of the hardest-hit areas appeared to be Hakuba, a ski resort town west of Nagano that hosted events in the 1998 winter Olympics. Japan's Kyodo news agency, citing fire officials, said at least one building collapsed in Hakuba, and that several people were injured. It wasn't clear whether the injured were at the building. The earthquake was felt in Tokyo, about 200 kilometers (124 miles) southeast of Hakuba. An apparent aftershock with a magnitude of 4.3 followed about 30 minutes later. No damage was reported at the Kashiwazaki-Kariwa nuclear power plant in nearby Niigaata prefecture. All of Japan's nuclear plants are offline following a massive earthquake and tsunami in 2011 that sent three reactors at the Fukushima Dai-ichi plant into meltdown. Fukushima is about 250 kilometers (155 miles) northeast of where Saturday's earthquake occurred. -- SPA 18:37 LOCAL TIME 15:37 GMT www.spa.gov.sa/w