<span style="color: #222222;">A powerful earthquake jolted northwestern Japan late yesterday, causing minor injuries to 21 people and a brief evacuation of coastal homes. <br />''<br />''However, a tsunami warning was withdrawn after a few hours.<br />'' <br />'' The business was returning to normal this morning, with trains mostly running as usual and electricity restored to thousands of homes that lost power temporarily. <br />''<br />''There were no reports of serious damage from the magnitude 6.7 quake. Minor sea level changes were detected by several coastal cities. <br />'' <br />''Japan's Meteorological Agency said the earthquake struck off the western coast of Yamagata about 50 kilometers southwest of the city of Sakata. </span>