First tsunami waves have hit Hawaii

Tsunami waves appear to be reaching Hawaii as water levels rose suddenly around Kahulai, Nawiliwili, Honolulu, and Pearl Harbour, according to data from the National Oceanic and Atmospheric Administration.

A wave has passed through the Midway Atoll island between Japan and Hawaii at 6ft (1.8m), Hawaii governor Josh Green says.

He says this was from the trough to peak of the wave, BBC reports.

"We're still expecting a significant wave," he adds, and they will only give the all clear when they feel there is "total safety".

In a briefing a little earlier, Honolulu Mayor Rick Blangiardi says the city is under a full tsunami alert, and calls for people in low lying areas to get to higher ground.

Earlier, the US coastguard in Honolulu issued an order for evacuation of commercial vessels from Hawaiian ports, with all harbours closed to incoming traffic.

Any vessels near Hawaii should remain offshore until tsunami waves have passed, the coastguard statement said.

Several flights bound for Hawaii have also been diverted mid-air, with many being redirected back to their airports of origin, according to flight tracking websites.

From Tokyo to Hawaii, from California to New Zealand, millions are on high alert amid fears of tsunamis.

A magnitude 8.8 earthquake hit far-eastern Russia at 11:25 local time, causing several minor injuries and widespread flooding.

Tsunami waves are expected to arrive at Hawaii's shores shortly, after Japan's northern coast saw waves of 40cm.

Japan has ordered 1.9 million Japanese people to evacuate, warning that tsunami waves could continue for more than a day.

California has asked people to stay away from the coast.

China, the Philippines, Indonesia, New Zealand and even Peru and Mexico have issued tsunami alerts.