A powerful earthquake jolted northwestern Japan late Tuesday, and officials warned of a possible tsunami up to one meter (3.3 feet) high along parts of the coast.

Some areas lost electrical power and some bullet train services were suspended, but there were no immediate reports of serious injuries or damage from the magnitude 6.8 quake. Only a minor swelling of the sea was observed in several cities about half an hour after it struck.

Japan’s Meteorological Agency said the earthquake was located off the western coast of Yamagata about 50 kilometers (30 miles) southwest of the city of Sakata.

Read more at Associated Press News.