An earthquake with a magnitude of 4.2 struck Hokkaido early Thursday, measuring a lower 5 on the Japanese seismic intensity scale to 7, the Meteorological Agency said.
The quake occurred at around 1:09 a.m. about 7 km underground in the Soya region of Hokkaido, the agency said. The agency did not issue a tsunami warning.
The magnitude was revised down from 4.4.
The temblor registered lower 5 intensity in the town of Toyotomi and 4 in the town of Horobetsu, the agency said. The weather agency defines lower 5 as an intensity at which many people are frightened and feel the need to hold onto something stable.
There were no immediate reports of injuries or property damage from the quake.
Nonetheless, the quake has increased the risk of falling rocks and landslides should another of similar intensity hit soon, a weather agency official said at a news conference in Tokyo, urging people in the northern region to be on alert for around the next week.
Following the quake, Hokkaido's government launched a task force headed by Gov. Naomichi Suzuki to deal with the situation.
A male official of Horobetsu in his 40s told Kyodo News, "I felt a strong shake while sleeping at my home." He added that the municipal government is gathering information on possible damage from the quake.