Tokyo -- The Pacific Tsunami Warning Center in Hawaii says a tsunami warning is in effect for a large swath of the Pacific after a magnitude 8.8 earthquake hit Japan.

A tsunami warning was in effect for Japan, Russia, Marcus Island and the Northern Marianas. A tsunami watch has been issued for Guam, Taiwan, the Philippines, Indonesia and U.S. state of Hawaii.

Japan's NHK says a small tsunami hit the shore near the epicenter around 3 p.m local time.

Japan's meteorological agency warns that a tsunami as high as 20 feet (6 meters) could strike the coast near Miyagi prefecture, closest to the epicenter.

The agency says the quake struck at 2:46 p.m. Friday at a depth of 6 miles (10 kilometers), about 80 miles (125 kilometers) off the eastern coast.