there was no tsunami damage to the facilities .
 
okinawa resident eric shepherd said his grandmother - in - law described it as the strongest quake she had tokyo | tokyo ( reuters ) - a strong earthquake hit japan 's southern island of okinawa early on saturday and japan 's weather agency issued a tsunami warning for up to 2 meters , but this was later lifted and there were no reports of major damage .
he told cnn that commanders in japan and hawaii were trying to get damage and casualty reports from u.s. military stations on okinawa , but had heard nothing in the immediate aftermath .
the quake was felt on okinawa , with shaking that lasted about 15 seconds , said lt .
about 20,000 u.s. troops -- mostly marines , along with navy and air force personnel -- are stationed on eight bases on okinawa , he said .
earthquakes are common in japan , one of the world 's most seismically active areas .
send photos , video ireporter kristina donaldson , who lives in central okinawa , said the quake " seemed to last longer than other ones we have experienced here . "
the u.s. geological survey said the 7.3 magnitude quake struck at 5:31 a.m. on saturday ( 2031 gmt on friday ) 52 miles east of the island 's capital of naha , a city of about 320,000 about 1,600 km ( 1,000 miles ) south of tokyo .