Tsunami alert after 7.4-magnitude earthquake strikes off Japan

The earthquake, which registered a preliminary magnitude of 7.4, struck off the coast of Sanriku in northern Japan at around 4.53pm (5.53pm AEST), at a depth of about 10 kilometers below the sea surface, the agency said.

Japanese Prime Minister Sanae Takaichi has urged residents in affected areas to evacuate immediately and said the government has set up an emergency task force, CNN reports.

“Residents of areas where tsunami warnings have been issued should immediately evacuate to higher ground or safer locations such as evacuation buildings,” Takaichi told reporters on Monday, according to national broadcaster NHK.

Authorities are making every effort to assess the damage, carry out emergency disaster relief measures such as search and rescue operations, and provide timely and accurate information to the public, Takaichi said.

“At this time we are still confirming the extent of human and material damage, but we will soon receive detailed reports and continue disaster response.”

A CNN producer on site in Tokyo reported feeling the building shaking for about seven minutes.

The operator of the bullet train service that runs between Tokyo and Shin-Aomori Station said the train service had been suspended due to a power outage caused by the earthquake, NHK reported.

A tsunami of about 80 centimeters was detected at Kuji Port in Iwate Prefecture, and a smaller tsunami of 40 centimeters was recorded at another port in the prefecture, the agency said.

A tsunami of up to three meters could hit the area, the agency said. In addition to the tsunami alert in Iwate and Aomori in northern and southeastern Hokkaido, the agency also issued a milder tsunami advisory for the coasts of Miyagi and Fukushima, south of the epicenter.

Another powerful 7.5 magnitude earthquake in December left dozens injured.

It has been 15 years since a magnitude 9 earthquake and tsunami on March 11, 2011, devastated parts of northern Japan, killing more than 22,000 and forcing nearly half a million people to flee their homes, most of them due to tsunami damage.

About 160,000 people fled their homes in Fukushima due to radiation from the tsunami-hit Fukushima Daiichi nuclear power plant. About 26,000 of them have not returned because they have moved elsewhere, because their place of residence is off-limits or because they are still concerned about radiation.