An earthquake with a preliminary magnitude of 6.7 hit Japan's northeastern region on Friday, prompting a tsunami advisory for waves up to 1 meter (39 inches) high from the Japan Meteorological Agency (JMA).
The quake struck at 11:44 a.m. off the coast of Aomori prefecture with a depth of 20 km (12 miles), after a bigger, 7.5-magnitude earthquake hit the same region late on Monday.
After Monday's earthquake, the government issued a special advisory warning residents across a wide area, from Hokkaido in the north to Chiba east of Tokyo, to be on alert for an increased risk of a powerful earthquake striking again within a week.
The tremor on Friday measured 4 on Japan's 1-7 seismic intensity scale.
Similar earthquake earlier this week was downgraded shortly after occurring
Japanese authorities lifted tsunami warnings on Tuesday hours after a powerful 7.5-magnitude earthquake shook northeastern regions, injuring at least 30 people and forcing about 90,000 residents to evacuate their homes.
The earthquake struck off the coast at 11:15 p.m. on Monday, and the Japan Meteorological Agency said a tsunami as high as 10 feet could hit the country's northeastern coast. Warnings were issued for the prefectures of Hokkaido, Aomori, and Iwate, and tsunamis from 7 to 27 inches high were observed at several ports, JMA said.
By early Tuesday, the JMA downgraded the warnings to advisories and later lifted all advisories. There were no reports of major damage.