TAIPEI, Taiwan — Rescue efforts resumed at dawn Thursday to try to free more than 100 people who remained trapped after a 7.4-magnitude earthquake struck off the east coast of Taiwan, as aftershocks continued to rattle the area around Hualien, the epicenter, and forecasts of rain raised concerns about more landslides.
The efforts have been complicated by a large number of aftershocks — at least 324 — in Hualien county, a scenic coastal region popular with tourists and hikers, and where the damage has been the heaviest. Taiwan officials said aftershocks of magnitude 6.5 to 7.0 were possible over the next three days.
Nine people died and more than 1,000 were injured in Wednesday’s quake, Taiwan’s largest in a quarter-century. There are fears both numbers could rise as rescuers venture into a rock quarry and a gorge where workers and tourists remain trapped.
Rescue helicopters pulled six people out of a quarry in Xiulin Township at 6 a.m. local time. More than 60 people remain trapped at that rock quarry, although they had access to water and electricity, according to Taiwan’s fire department.
A group of hotel workers and tourists remained trapped inside a long and twisting tunnel within the Taroko Gorge national park. Officials said the nearly mile-long tunnel known as Jiuqudong, or the Tunnel of Nine turns, had partially collapsed.
More than 30 people were still missing in the gorge, the fire department said Thursday. Rescue workers were using drones and helicopters to search for others trapped in the park, the entrance to which was cut off by fallen boulders. A team of 200 rescuers was attempting to reach the group in Jiuqudong by foot.
Drone footage posted by Taiwan’s Minister of the Interior, Lin Yu-chang, showed some of the residents trapped in the park under a damaged but intact metal tunnel, waving at the camera. Local media reports showed rescue teams airlifting sleeping bags and cans of congee and soymilk to the trapped quarry workers.
The quake, which occurred just before 8 a.m. Wednesday and which the U.S. Geological Survey measured at 7.4 in magnitude, was felt across Taiwan and as far as China’s southeastern provinces. It triggered tsunami warnings in Japan and the Philippines that were later lifted.
Taiwan, home to more than 23 million people, sits on the Ring of Fire, a region of the Pacific Ocean that is the world’s most seismically active zone. The last time it saw a quake this strong was in 1999, when a 7.6-magnitude tremor struck central Taiwan, killing more than 2,400 people.
After that earthquake authorities mandated stricter construction codes and programs to upgrade old buildings — efforts that experts say have helped keep the death toll relatively low.
On Thursday, schools and businesses in Hualien reopened and the local railway line also resumed operation. Aftershocks continued to be felt throughout Taiwan, prompting the Central Weather Administration to say that they would stop announcing tremors smaller than magnitude 3.o.
Taiwan’s president-elect, Lai Ching-te who takes office next month, visited Hualien Wednesday and said the government’s top priority was to rescue those trapped.
More than 300 households in Hualien do not have power and almost 10,000 homes in the area have lost access to running water, according to Taiwan’s Ministry of Economic Affairs.
What happens in Taiwan has global repercussions. Taiwan is a key manufacturing hub for many of the world’s advanced computer chips. Taiwan Semiconductor Manufacturing Co., the world’s most important maker of high-tech computer chips based in central Taiwan, said its facilities were not seriously damaged by Wednesday’s earthquake.
Within 10 hours of the earthquake, 70 percent of production had been restored, the company said in a statement late Wednesday. None of the company’s high-end “lithography” machines, among the most complex pieces of equipment in the world, were damaged, TSMC said.