Rescue teams in Taiwan are striving to reach over 600 individuals stranded following the island's most severe earthquake in a quarter of a century.

One survivor described how the seismic tremors triggered rockslides resembling bullets around the coal mine where he was employed.

Measuring 7.4 on the Richter scale, the earthquake struck near the eastern county of Hualien, resulting in nine fatalities and over 1,000 injuries.

Although helicopters have managed to evacuate some individuals stuck in tunnels and near a national park, 34 people are still unaccounted for.

The official count of those trapped or stranded surged significantly, from around 100 to 660, as phone signals were restored in the mountainous regions on Thursday.

Most of those affected are guests and staff of a remote hotel, unable to depart due to damaged roads. Authorities are now strategizing the best approach to extract them.

Local reports indicate that food supplies have been dropped to dozens trapped in these remote areas.

Detailing the harrowing experience, a survivor named Chu recounted, "The mountain started raining rocks like bullets, we had nowhere to escape to, everyone ran beside the sandbags for cover," to Taiwan's Central News Agency.

Among the deceased were three hikers on a trail leading towards Taroko National Park, situated just outside Hualien.

In Hualien city, the county's capital hit by the earthquake, relief operations are underway swiftly. Workers are employing excavators and heavy machinery to demolish several compromised structures.

The BBC observed relief workers on Thursday morning clearing huge boulders, some as large as cars, from near railway lines to restore normal train services.

Efforts are also focused on reinforcing a 10-story building known as the Uranus building, which has tilted downward since the quake, to prevent collapse in case of further aftershocks.

According to local reports, a female teacher lost her life in the Uranus building while attempting to rescue her cat.

Hsu Chiu-yueh, who witnessed the building collapse, recounted, "It was so shaky I could barely walk. I was really scared. I felt my legs were not in control anymore. Thanks to my colleagues, they dragged me so we could get out."

"There was a lot of dust coming into our building on our way out... We [later] realized that it came from the building across the street that had partially collapsed," said the 50-year-old.

Another resident of Hualien described how the quake disrupted her home. "I was just getting out of bed when a clothes rack and a low cabinet fell over," Ocean Tsai told BBC Chinese.

"It kept getting stronger, and I started worrying about our belongings at home. Fortunately, apart from the motorcycle tipping over, the damage was minimal."

The earthquake, which struck 18km (11mi) south of Hualien, was followed by more than 200 aftershocks, dozens of which were at least 6.5 magnitude or more, hindering search and rescue efforts. Taiwanese authorities expect there to be more aftershocks in the next few days.

Pictures show how the road outside Hualien's Qingshui tunnel - one of many winding roads that run along Hualien's rocky coastline - had simply fallen away.

Routes like Qingshui are popular among tourists because of their spectacular views from the mountains out across the Pacific Ocean. But they are also known to be treacherous, not least because of the possibility of landslides.

Further north, the capital Taipei was also shaken violently with footage showing damaged buildings and people being evacuated. Local TV stations aired clips of smashed vehicles and stores in disarray.

"The earthquake is close to land and it's shallow. It's felt all over Taiwan and offshore islands... It's the strongest in 25 years," Wu Chien Fu, the director of Taipei's Seismology Centre said on Wednesday.

Power cuts and internet outages were reported across the island.

The earthquake also triggered tsunami alerts earlier in the day on Wednesday in nearby Japanese and Philippine islands, but these alerts were later downgraded.

While Taiwan has a history of quakes, both locals and foreigners who have lived in Taipei for years say this is the strongest quake they have experienced in decades.

This is serious