Fire safety officials were quoted by Taiwan media as saying at least nine people were killed in Hualien County, including three hikers and one engineering worker struck by falling rocks while on a trail, and at least 821 were injured.
Rescue teams were working to free at least 127 people believed to be trapped in rubble or needing rescue, according to the news channel SETN.
The National Fire Agency said authorities have lost contact with 50 people in minibuses after the quake downed phone networks.
In the capital, Taipei, vehicles pulled over on the side of the road and the city’s subway service was briefly suspended while tiles fell from older buildings and furniture was knocked over from the force of the earthquake.
A series of aftershocks were felt in the capital about 15 minutes later and continued over the next hour. Authorities said aftershocks could continue for the next three to four days due to the earthquake’s intensity.
Stacy Liu, a Chinese teacher in Taipei who was teaching a class online when the earthquake struck, said it revived childhood memories of Taiwan’s worst quake in recent memory in 1999, when more than 2,400 people were killed.
“I was freaking out. I felt like scary things were going to happen all over again because I’ve been through 1999, so I know how scary it can be,” Liu told Al Jazeera.
“I was taking out [construction] helmets, prepping our guinea pigs, and putting some water and snacks under the table in case something crazy happened.”
“I thought it was just going to be a small earthquake at first, but then it definitely became a lot more violent than I’m used to. We have a sliding glass door, which is the entry to our balcony and apartment, and it swung open, which I did not know was possible,” Phan-Stattmen told Al Jazeera.
“Then [our cat] Beef ran around and ran to the bedroom, and all the books started to fall.”
Wu Chien-fu, the director of Taiwan’s Seismological Center, said the earthquake was the strongest to hit the island since the 1999 quake.
“The earthquake is close to land, and it’s shallow. It’s felt all over Taiwan and offshore islands,” Wu told reporters.
Taiwan’s earthquake alert system, which typically provides warnings minutes in advance, did not activate before the quake.
After tsunami warnings in Taiwan, Japan and the Philippines, the Pacific Tsunami Warning Center in Hawaii, in the United States, said late on Tuesday that the threat had “passed.”. No damage or casualties were reported from quake-generated waves.
The Japan Meteorological Agency lifted all tsunami advisories after earlier urging residents on the islands of Okinawa, Miyakojima and Yaeyama to evacuate as it warned of waves of up to 3 metres (9.8ft) high.
The agency said a wave measuring about 0.3 metres (1ft) high was detected on the coast of Yonaguni Island about 15 minutes after the earthquake.
Okinawa’s main airport suspended flights after the alert.
The Philippine seismology agency cancelled its alert after warning that coastal areas would experience “high tsunami waves.”
Taiwan lies on a tectonic belt, known as the Pacific Ring of Fire, where about 90 percent of all earthquakes occur.
The self-governed island has strict building regulations and disaster awareness programmes to reduce casualties from earthquakes.
(Al Jazeera)