Millions of US citizens are under threat of a huge tsunami after a massive 8.8 magnitude earthquake struck off the coast of Russia.

BBC News reports that the first waves triggered by the seismic earthquake have reached Hawaii, with a 4ft (1.2m) wave recorded off Oahu.

Residents in Hawaii had already been told to evacuate from the coastal areas as the risk became apparent following the earthquake in the far east of Russia.

How powerful is the earthquake and where did it strike?

The sixth-biggest earthquake on record hit Russia overnight as a kindergarten in Petropavlovsk collapsed following the 8.8 magnitude quake.

Several were left injured as a result of the earthquake, while tsunami waves hit the coastal town of Severo-Kurilsk.

Oleg Melnikov, a regional health minister, told the TASS state news agency: “Unfortunately, there are some people injured during the seismic event. Some were hurt while running outside, and one patient jumped out of a window. A woman was also injured inside the new airport terminal.

“All patients are currently in satisfactory condition, and no serious injuries have been reported so far.”

Citizens have been leaving Hawaii in masses (EUGENE TANNER/AFP via Getty Images)

What is the tsunami warning and who is affected in the US?

The California and Oregon border has now been placed under a tsunami warning, which basically means ‘take action’, according to the US National Weather Service.

Meanwhile, advisories continued to be issued for the West Coast of the US, as officials continue to monitor the threat.

President Donald Trump took to Truth Social to issue a warning to millions of Americans regarding the ongoing risk of a tsunami.

He penned: “Due to a massive earthquake that occurred in the Pacific Ocean, a Tsunami Warning is in effect for those living in Hawaii. A Tsunami Watch is in effect for Alaska and the Pacific Coast of the United States. Japan is also in the way. Please visit tsunami.gov/ for the latest information. STAY STRONG AND STAY SAFE!”

Severo-Kurilsk in Russia has been severely impacted by the earthquake (Kamchatka of Geophysical Survey/Anadolu via Getty Images)

Where will the tsunami hit? Full list of areas at risk revealed

It’s not just the US that is being impacted by the earthquake as more than 1.9 million people in Japan have been told to evacuate.

The country’s weather agency has said a tsunami wave of 4.3ft has reached the northern Iwate prefecture.

Varying tsunami alerts have been issued in parts of China, the Philippines, Indonesia, Guam, Peru and the Galapagos Islands.

As per the Financial Express the full list of islands under threat are:

• Guam
• Palau
• Solomon Islands
• Marshall Islands
• Midway Atoll
• Wake Island
• Johnston Atoll
• Northern Mariana Islands
• Yap
• Pohnpei
• Korsae
• Chuuk
• Aleutian Islands

How to stay safe during a tsunami

The National Weather Service says those who are in a tsunami hazard zone and receive an official warning should stay away from the coast until the alert if lifted.

Furthermore, if you are asked to evacuate, then you should head to high ground or inland as quickly and safely as possible.

It’s also advised you set up multiple ways to receive warnings prior to a potential tsunami, including text message alerts from your local government.

Featured Image Credit: NOAA