Japan hit by strong earthquake Last Updated Nov 22, 2014 10:29 AM EST TOKYO -- 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. The magnitude-6.8 earthquake struck near Nagano city at 10:08 p.m. at a depth of 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. CBS News' Lucy Craft reports that several sections of major highways were closed for inspection. 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 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 155 miles northeast of where Saturday's earthquake occurred. National broadcaster NHK reported that a landslide blocked a road after the quake struck. NHK also said 200 homes were without power, and that Shinkansen bullet train service in the area was temporarily suspended. It also reported that several people were injured.