TOKYO (AP) — A strong earthquake late Saturday struck a mountainous area of central Japan that hosted the 1998 winter Olympics, knocking down at least 10 homes in a ski resort town and injuring several people, officials said.

The magnitude-6.8 earthquake struck near Nagano city shortly after 10 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.

One of the hardest-hit areas appeared to be Hakuba, a ski town west of Nagano that hosted events in the 1998 games. Ten homes collapsed there, said Shigeharu Fujimura, a Nagano prefecture disaster management official.

Nine people were trapped underneath the collapsed houses, but they all were rescued, and none had life-threatening injuries, said Hakuba official Tomoyuki Shimokawa.

Many houses also lost water, apparently because of a ruptured pipe, and landslides on two major roads blocked access to some areas. “We are afraid there could be some areas that may have been isolated, so we need to conduct a thorough assessment of damage after sunrise,” Fujimura said.

Ryo Nishino, a restaurant owner in Hakuba, told Japanese broadcaster NHK that he had “never experienced a quake that shook so hard. The sideways shaking was enormous.” He said he was in the restaurant’s wine cellar when the quake struck, and that nothing broke there.

Nagano prefectural police said there were several reports of injuries in Hakuba and Nagano city.

The earthquake was felt across much of northern Japan and in Tokyo, about 125 miles southeast of Hakuba.

Japan’s Nuclear Regulation Authority said no abnormalities were reported at three nuclear power plants in the affected areas. All of Japan’s nuclear plants are offline following a magnitude-9.0 earthquake and massive 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.

The quake was followed by 21 aftershocks, said Yohei Hasegawa of the Meteorological Agency’s earthquake and tsunami division. He warned of further aftershocks and urged residents to watch out for landslides.