South Korea is looking into potential casualties of its nationals in earthquake-struck Japan, but has yet to confirm any casualty, South Korean foreign ministry?in Seoul?said Friday.

A magnitude-8.9 earthquake hit the northeast coast of Japan earlier in the day, prompting the South Korean embassy and consulate there to set up an emergency task force to assess damage.

The embassy there advised South Korean nationals not to access seashore and rivers, with the entire Japanese coast under a tsunami warning, the foreign ministry said.

Some 910,000 South Koreans are in Japan, with 10,000 of them near the city of Sendai in northern Japan, according to the ministry.