Japan saw tsunami waves of about 1 meter high in coastal areas on Sunday but no major damage or flooding after the eruption of an underwater volcano off Tonga led to evacuation orders for nearly 230,000 citizens.

Japan's weather agency issued tsunami warnings and advisories in the early hours for the Pacific coast from Hokkaido to Okinawa, but these were all lifted in the afternoon, after around 14 hours.

The agency said slight sea-level fluctuations may continue for some time, but there is no risk of disaster. However, it cautioned over marine activities such as those done underwater and fishing.

While there were no serious human casualties, some fishing boats were capsized and the warnings caused delays or cancellations to public transport.

Up to 229,000 people in eight prefectures -- Aomori, Iwate, Miyagi, Chiba, Tokushima, Kochi, Miyazaki and Kagoshima -- were asked to flee from the seaside, according to the Fire and Disaster Management Agency.

Some high school students in the prefectures who were to sit for the 2-day nationwide university entrance examinations from Saturday had to adjust to new time schedules.

A 1.2-meter wave was observed on Amami Island in Japan's southwest shortly before Saturday midnight, while a 1.1-meter one later arrived in Iwate Prefecture in the northeast which was hit by the 2011 deadly tsunami.

Train, air and maritime transport services were affected, with 27 Japan Airlines domestic flights including to and from Amami canceled. A total of 22 ships in Kochi Prefecture, western Japan, were found to have capsized or drifted.

Concerns about tsunami across the Pacific from the massive volcano eruption on Saturday afternoon that prompted residents on Tonga to evacuate have largely abated, but the extent of the damage remains unknown.

As communication with the South Pacific island country remained significantly cut off, neighboring countries were trying to discover the extent of damage or casualties.

New Zealand Prime Minister Jacinda Ardern said that communication due to the eruption has been difficult.

"As yet there are no official reports of injuries or deaths," Ardern said in a press conference, although contact has not yet been made with outer islands and coastal areas beyond the capital Nuku'alofa.

Ardern added there have been "significant" impacts on the foreshore on the northern side of the capital, citing reports that boats and large boulders had been washed ashore. No official damage assessments are available yet, however.

A volcano about 65 kilometers north of Nuku'alofa erupted Saturday, with the entire island nation reportedly hit by tsunami as high as 80 centimeters. Other Pacific islands and the United States also observed tsunami, but there have been no reports of major damage or casualties.

Tonga is a nation of about 170 islands, of which 36 are inhabited. It is home to about 107,000 people, and as of October 2020, there were 35 Japanese residents.

Nuku'alofa has been covered in a thick film of volcanic dust, sparking concerns around access to clean drinking water and respiratory issues.

Ardern reportedly said the undersea cable has been impacted, and New Zealand officials are trying to establish what was needed.

Tsunami of about 1 meter reached New Zealand, which is near Tonga, and more than 1 meter for Pacific islands such as Vanuatu, as well as Chile.

In Alaska and California, tsunami waves of more than 1 meter were also observed, according to the U.S. National Oceanic and Atmospheric Administration.

==Kyodo

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