Japan lifted a tsunami advisory issued for Okinawa Prefecture on Wednesday afternoon, after earlier warning of the potential for large waves hitting parts of the prefecture, following a powerful earthquake that rocked Taiwan.

The magnitude 7.7 quake had initially prompted a forecast of waves of up to 3 meters for some areas in Okinawa, with residents strongly urged to evacuate coastal areas. The warning was later downgraded to a tsunami advisory at 10:40 a.m., with the expected height of waves reduced to 1 meter. That advisory was lifted as of 12 p.m.

Tsunami measuring at least 30 centimeters were observed at Yonaguni and Miyako islands, while waves as high as 20 cm also reached Ishigaki Island.

There were no immediate reports of damage or casualties in the southern prefecture, the government’s top spokesman told a news conference, but people were still urged to stay away from the coast.

“There haven’t been reports of casualties or buildings damaged so far (from Okinawa). Besides that, we are aware of emergency calls regarding traffic in the prefecture,” Chief Cabinet Secretary Yoshimasa Hayashi said.

“We ask that everyone in the area stay alert to information from local authorities and the Meteorological Agency, as well as from television and radio, and act calmly, without being misled by uncertain information — please do not panic. Help each other and remain calm,” he added.

The massive quake — the largest to hit Taiwan in 25 years — prompted tsunami warnings for the island and knocked out power in some areas of the island’s east, with television footage showing collapsed buildings. Media reports said at least nine people were believed to have been killed and more than 900 injured.

Two buildings were tilted in the city of Hualien and one factory building collapsed in New Taipei City, Taiwan’s Central News Agency reported. Stones and bricks fell off in multiple places, including at the Chiang Kai-shek Memorial Hall in Taipei, and landslides occurred on highways.

​​A hotel reception staff at OLAH Poshtel in Hualien, who only gave her last name as Ou, said there were buildings in the city center that were tilted or collapsed. The hotel also offered a free-cancellation option for reservations until Friday.

China’s state media reported that the quake was felt in multiple cities in Fujian and Guangdong provinces across the Taiwan Strait, as well as in Shanghai, Zhejiang, Jiangsu and Jiangxi.

Tsunami warnings were also issued in the coastal areas of several provinces of the Philippines, though these were lifted hours later.

This was the first time a tsunami had been detected in Japan since a powerful earthquake hit the Noto Peninsula area in Ishikawa Prefecture on New Year’s Day, with NHK warning viewers earlier via a large banner reading “Evacuate! Run!”

According to Japan’s Meteorological Agency, Wednesday’s quake was as big as — if not bigger — than the Noto temblor, registering a magnitude 7.7. The quake had also been recorded as high as a 4 on the 7-point Japanese shindo seismic intensity scale in Yonaguni, which sits just 110 kilometers (70 miles) from Taiwan.

The United States Geological Survey (USGS) said the quake, which struck at 8:58 a.m., had registered a magnitude 7.4, originating 18 km south southwest of Hualien, Taiwan, at a depth of 34.8 km, while Japan’s meteorological agency said the quake had a magnitude of 7.7 and occurred at a depth of 23 km.

Even after the tsunami advisory was lifted, people were still urged to continue to stay away from the coast, with the continued likelihood of waves rushing the shore multiple times and the height increasing suddenly, a Meteorological Agency official told a news conference Wednesday morning.

People were urged to stay vigilant, given that the tsunami that resulted from the March 2011 Tohoku earthquake also began with waves that were just a couple of centimeters high.

Given that Okinawa is a tourism hub, and many visitors — both foreign and domestic alike — are unfamiliar with the area and tsunami protocol, Okinawa residents were being asked to help them, if necessary.

At Naha Airport, commercial flights resumed after an earlier suspension Wednesday morning, although throngs of passengers crowded the airport due to delays, NHK reported.

The weather agency also warned that aftershocks — possibly as strong as the initial quake — could continue over several days.

Agency officials noted that there had been a 10% to 20% possibility that a tremor of the same scale could occur within the week, citing past major earthquakes. They said the chances were “especially high” over the first two to three days, and urged residents to stay alert.

Regarding the earthquake in Taiwan, Prime Minister Fumio Kishida expressed his condolences and intention to offer support.

"We are truly grateful for the heartwarming support we received from our dear friends in Taiwan during the Great East Japan Earthquake and the recent Noto Peninsula Earthquake," he wrote on X. "Japan is ready to provide necessary support to Taiwan, our neighbor across the sea, in its time of need."

Staff writer Francis Tang contributed to the report.

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