At least six people were injured when thousands fled for higher ground after Japanese authorities issued an imminent tsunami warning following a powerful 7.4 earthquake and a series of aftershocks off Fukushima Prefecture.

LIVE UPDATES: 7.3 Fukushima quake & tsunami

The quake struck 67km northeast of Iwaki, a city located in the southern part of the Hamadori coastal region of Fukushima Prefecture, Japan.

This is an image of the Fukushima Nuclear Plant from NHK with the text "evacuate immediately." Unsettling #japanquakepic.twitter.com/9sYIFD8uuP — Jake Milstein (@MilsteinKIRO7) 21 ноября 2016 г.

The initial 7.4 magnitude quake struck at 5:59am JST at a depth of 25km, according to Japan’s Meteorological Agency (JMA). At least seven aftershocks followed the initial jolt.

“Tsunami warnings or advisories are currently in effect,” the agency said.

Officials issued a tsunami warning and announced the evacuation of the areas close to the shore. Residents near the coast were told to seek higher ground and not to visit the shore until the warning is lifted.

“Damage due to tsunami waves is expected. Evacuate immediately from coastal regions and riverside areas to a safer place such as high ground or an evacuation building. Tsunami waves are expected to hit repeatedly. Do not leave safe ground until the warning is lifted,” JMA warned.

Meanwhile the Pacific Tsunami Warning center has issued “a tsunami threat message for other parts of the Pacific located closer to earthquake,” while stressing that there is no tsunami threat for the US state of Hawaii.

Tsunami advisories have also been issued for the Pacific coast of Aomori Prefecture, Iwate Prefecture, Miyagi Prefecture, Ibaraki Prefecture and the Kujukuri and Sotobo areas of Chiba Prefecture.

The tsunami warnings were later downgraded to advisories, indicating that the threat was lower than initially expected.

NHK News Japan warned those living on the coastline in Fukushima to “hurry up and run away.”

The news outlet also reportef that the Coastguard issued a navigational warning in Fukushima Prefecture and the northern part of Ibaraki Prefecture, for ships to avoid the area.

At least six people suffered minor injuries during the quake and tsunami, NHK reported.