A 7.7-magnitude earthquake has struck off the coast off Japan, triggering a tsunami warning for swathes of the northeastern coast.
The country's meteorological agency warned tsunami waves as tall as three metres were expected to hit parts of Japan's coast.
Initial waves proved to be considerably smaller than feared, although the country’s prime minister said a report of damage was being assessed.
Areas expected to be the worst-hit include the coastlines along central Pacific Hokkaido, and Aomori and Iwate prefectures.
Scroll down for the latest updates...
Aftershocks recorded
15:34 , Tom PlaceA number of aftershocks have been felt today in Japan since the 7.7 magnitude quake hit earlier.
The Japan Meteorological Agency has recorded smaller earthquakes of 5.4, 4.9 and 4.5 off the coast of Sanriku, where the large quake took place, as well as a 4.3 magnitude earthquake off the Kiisuido Strait, in the south of the country.
'Relatively high' risk of second, large earthquake
14:46 , Tom PlaceThe Japanese Meteorological Agency has said that the possibility of a large earthquake following today's 7.7 one is relatively high.
They say that probability of the larger earthquake is only about one in 100 - roughly a 10x increase in risk compared to normal conditions when it is usually 0.1% or less.
It is no guarantee that a large quake will happen again, and there is no need for advance evacuation.
Tsunami warnings downgraded to advisories
14:06 , Tom PlaceJapanese authorities have now downgraded all tsunami warnings in place around the northeastern coast to advisories.
A number of regions had tsunami warnings, the second-highest alert ion the Japanese system. They are issued for waves expected to be up to three metres high.
Tsunami Advisories are the lowest-level alerts issued for waves below one metre.
Authorities continue to advise people to remain away from the coast and to avoid large bodies of water until the advisories have been lifted.
Earthquake revised to 7.7 magnitude
12:47 , Tom PlaceJapanese authorities have revised the magnitude of the earthquake to 7.7, having initially announced it as having a magnitude of 7.5.
Authorities have also confirmed the depth the quake occurred at to be 19km, having previously said it occurred at 10km.
Quake had intensity of 5+ on Japanese scale
11:48 , Tom PlaceAccording to NHK, today’s quake registered an intensity of 5+ on the Japanese seismic scale of 0 to 7.
It struck off the coast of Sanriku at 8:52am UK time at a depth of 10km.
Houses lose power and bullet trains suspended
11:32 , Tom PlaceJapan’s Cabinet Secretary Minoru Kihara has said that residents should stay inland until tsunami warnings are lifted.
Around 100 households are currently without power, he says.
A number of bullet train services in the northeast of the country have been suspended, including the Tohoku Shinkansen line, the Yamagata Shinkansen line and the Akita Shinkansen.
Earthquake sirens sound
11:25 , Tom PlaceFootage posted on X shows tsunami alarms going off in Hakodate, a major port city in Hokkaido Prefecture.
Hakodate, Japan, as #tsunami alarms going & many ships heading to sea - including us! @SkyNews https://t.co/bGB0UHHvQ6 pic.twitter.com/mfSoOSobJJ
— Alastair Bruce (@AlastairBruce_) April 20, 2026
NHK footage shows waves hitting coast
11:16 , Tom Place
Possible aftershocks for a week
10:58 , Tom PlaceThe Japan Meteorological Agency has cautioned people in the area against possible aftershocks for about a week.
These warnings are standard procedure following a major earthquake.
80cm tsunami detected
10:39 , Tom PlaceA tsunami of about 80 centimetres (2.6ft) has been detected at the Kuji port in the Iwate prefecture.
Residents have been advised to stay away from the coast or along rivers, and to take shelter on higher ground.
Residents in 11 towns in the Iwate prefecture have been issued non-binding evacuation advisories.
No abnormalities at Fukushima
10:32 , Tom PlaceNHK has reported that the operator of the Fukushima Daini nuclear power plant says there are no abnormalities there.
Around 26,000 of those who left their homes after the meltdown caused by the tsunami in 2011 have still not returned to the area.
Many resettled elsewhere, with some towns remaining off-limits and lingering concerns about radiation.
Bigger tsunami may hit after first wave
10:21 , Tom PlaceIn their news conference, officials from the Japan Meteorological Agency have warned people to evacuate to higher ground and keep watch for landslides or similar earthquakes later this week.
The agency has also warned that a bigger tsunami may hit after the first wave.
Tsunami warnings in parts of Hokkaido and Iwate prefectures have also now been issued.
Map showing earthquake warnings
10:17 , Tom PlaceThe below map, provided by the Japan Meteorological Agency, shows the epicentre of the quake with a red X.
The areas highlighted in red have tsunami warnings, while the areas in yellow are labelled Tsunami Advisory.
Japan Meteorological Agency news conference
10:14 , Tom PlaceThe Japan Meteorological Agency has just started a news conference - we will bring you all the key lines.
First waves reach Japanese coast
10:07 , Tom PlaceJapan’s public broadcaster NHK has reported that a tsunami has been observed approximately 50km off the coast of Aomori, a prefecture in the northern part of Japan's main island.
The first tsunami waves are also reaching Iwate prefecture, with a wave as high as 40cm recorded in Miyako port.
Authorities checking for abnormalities at nuclear plants
10:03 , Tom PlaceJapanese authorities are checking the Onagawa nuclear power plant for any abnormalities following the earthquake.
Japanese news site Kyodo has reported that there are currently no abnormalities at the nuclear plants in the prefectures of Aomori and Miyagi.
The Fukushima Daiichi nuclear power plant was hit by a 9.0 magnitude earthquake and tsunami in March 2011, causing 160,000 people to flee their homes
Three metre tsunami could hit coast soon
09:53 , Tom PlaceJapan’s NHK public television said a tsunami of up to three metres (10ft) could hit parts of Japan shortly.
Warnings have been issued for Iwate prefecture, the central part of the Pacific coast for Hokkaido, and the Pacific coast of Aomori Prefecture.
Advisories have been issued for other parts of the Pacific coast of Hokkaido and Aomori prefectures, as well as the Miyagi and Fukushima prefectures.
Quake felt hundreds of miles away
09:51 , Tom PlaceIt has been reported that the quake was felt hundreds of miles away from the epicentre in Tokyo.
Japan's Prime Minister Sanae Takaichi has urged people in quake-affected areas to seek higher ground.
7.4 magnitude earthquake
09:48 , Tom PlaceThe Japan Meteorological Agency have confirmed that an earthquake registering a preliminary magnitude of 7.4 occurred off the coast of Sanriku in northern Japan today.
It occurred at around 4.53pm local time (7.53am GMT) at a depth of about 10 kilometres below the sea surface.
