Tsunami warnings issued following a magnitude-7.7 earthquake off Taiwan on Wednesday disrupted air, bus and ferry services, and local residents and tourists were warned to evacuate to higher ground in many islands of Japan's southern prefecture of Okinawa.

Tsunami alert sirens sounded on Okinawa Island and several other islands, with some residents frightened while others fleeing calmly.

"I was surprised when my mobile phone's alarm rang loud. There have been a lot of earthquakes recently, so I'm scared," said an employee at a car rental agency on Ishigaki Island. The epicenter was at a depth of 23 kilometers, some 250 km west-southwest of Ishigaki.

On Yonaguni Island, about 110 km east of Taiwan, around 40 local residents took shelter at a local middle school. "They were calm when evacuating," its vice principal said.

Following the 8:58 a.m. earthquake, small tsunami of up to 30 centimeters reached the islands of Yonaguni, Ishigaki and Miyako, Japan's weather agency said.

The quake registered 4 on the Japanese seismic intensity scale of 7 in Yonaguni, the agency said.

At Naha airport located on the western coast of Okinawa Island, more than 90 flights were canceled, with passengers urged to move to higher floors of the terminal building.

Naha airport in the southern Japan island prefecture of Okinawa is crowded on April 3, 2024, after operations were temporarily suspended following a tsunami warning due to a powerful earthquake off Taiwan. (Kyodo) ==Kyodo

"I hope I can go home without any trouble," said a woman who was visiting Okinawa from Nagoya in central Japan.

Okinawa Bus said it moved dozens of its buses operating in Naha, the prefectural capital, to at least over 3 meters above sea level, while temporarily suspending its airport shuttle bus service.

Anei Kanko, which operates a ferry service between Ishigaki and nearby islands, evacuated passengers at its terminal to the rooftop of a nearby hotel.

Several ferries had departed before the tsunami warnings were issued and stayed at sea until the warnings were lifted, the operator said.

"We could respond without any confusion or trouble," said Eisuke Morimura, chief of the sales planning section at Anei Kanko.

Some people evacuated to facilities of the Self-Defense Forces with around 30 children and staff of a nearby nursery school fleeing to the Air Self-Defense Force's Onna base.

Related coverage:

Japan ready to support Taiwan following strong quake: PM Kishida

M7.7 quake in Taiwan kills 9, injures more than 800