An 80-centimetre (31-inch) tsunami wave hit a port in northern Japan Monday after a powerful 7.4-magnitude earthquake struck the region, Japan's Meteorological Agency (JMA) said.

The wave was observed at 5:34 pm (0834 GMT) at a port in Kuji, Iwate, JMA said. It previously said a 70-centimetre wave had struck at 5:32 pm.The earliest tsunami waves could reach the northern shoreline immediately, the weather agency said.

"Evacuate immediately from coastal regions and riverside areas to a safer place such as high ground or an evacuation building," it said, warning that damage due to tsunami waves was expected.

"Tsunami waves are expected to hit repeatedly. Do not leave safe ground until the warning is lifted," it said.

Footage from national broadcaster NHK did not show any immediate visible damage around several ports in Iwate. The prime minister's office said it had set up a crisis management team.

"For those of you who live in areas for which the warnings have been issued, please evacuate to higher, safer places such as higher ground," Prime Minister Sanae Takaichi told reporters, adding that the government was trying to confirm whether there were any casualties or property damage.

Source:Ndtv