CNN–A major earthquake with a magnitude of 7.4 struck Taiwan’s eastern coast Wednesday, according to the US Geological Survey, the strongest to hit the island in 25 years.

The quake hit at 7:58 a.m. local time 18 kilometers (11 miles) south of Hualien city and at a depth of 34.8 kilometers (21 miles), USGS said. It was followed by several strong aftershocks with tremors felt across the island, including by CNN staff in Taipei.

Reports of preliminary damage have emerged, with people trapped in collapsed buildings in Hualien County, thousands of homes left without power and a major highway along the island’s east coast shut to traffic due to major damage from landslides and rockfalls, according to Taiwanese officials.

Taiwan’s Central Weather Administration spokesperson warned that powerful aftershocks as high as magnitude 7 are expected to occur until the end of the week.

The quake prompted tsunami warnings in Taiwan, southern Japan and the Philippines, with waves less than half a meter observed along some coasts, and prompting airlines to suspend flights. The tsunami warning in Japan was later lifted, according to the Japan Meteorological Agency.

In Taiwan, military personnel have been dispatched to help with disaster relief and schools and workplaces suspended operations as aftershocks hit the island, according to the Defense Ministry.

Taiwan’s outgoing President Tsai Ing-wen said Wednesday she had ordered her administration to “immediately” get “on top of the situation and understand local impacts as soon as possible.”

Tsai also told the administration to “provide necessary assistance, and work together with local governments to minimize the impact of the disaster.”

Taiwan is regularly rocked by earthquakes due to its location on the Pacific Ring of Fire, which runs around the edge of the Pacific Ocean and causes massive seismic and volcanic activity from Indonesia to Chile.

Wednesday’s quake is the strongest to hit Taiwan since 1999, according to the Central Weather Administration. That powerful 7.7 magnitude quake hit 93 miles (150 kilometers) south of Taipei, killing 2,400 people and injuring 10,000 others.

Collapsed buildings, highway damaged

At least 26 buildings collapsed in the earthquake Wednesday, 15 of which are in Hualien County, Taiwan’s Central Emergency Command Center (CEOC) said.

More than 91,000 households are without electricity, according to CEOC, which said the island’s government-operated Taipower Company is working to fix the issue.

Footage posted on social media showed several collapsed buildings in Hualien and residents helping trapped people escape through the window of a damaged apartment complex.

Meanwhile, video broadcast by CNN affiliate TVBS showed cellphone and security camera footage of the moment tremors struck homes and businesses across the island. One clip showed power lines swaying violently above a street and another saw chandeliers shaking in a restaurant.

Large boulders could be seen strewn across the Suhua Highway, along Taiwan’s east coast, with several tunnels broken — including one split in half, footage from TVBS showed. CNN affiliate SET News shows the front of a car smashed by fallen rocks.

The Eastern District Maintenance Engineering branch of the Highway Bureau had recorded at least nine rockfalls and landslides in the Suhua Road Corridor of Provincial Highway 9, which has been closed to traffic.

Another highway connecting the west coast with the east of Taiwan was also damaged by falling rocks, with at least 12 cars hit and nine people injured, TVBS reported.

Hualien County near the quake’s epicenter is home to about 300,000 people and close to Taroko Gorge, a popular tourist destination. A magnitude 6.2 quake hit near Hualien in 2018, killing at least 17 people and injuring more than 300 others.

Tsunami waves

The quake sparked tsunami warnings across the region as authorities ordered evacuations.

In Taiwan’s Chenggong, about 100 kilometers (62 miles) south of the quake’s epicenter, tsunami heights reached almost half a meter. The island’s Central Weather Administration issued an alert advising residents to evacuate to higher ground.

The Japan Meteorological Agency also issued a tsunami alert for the southern Miyakojima and Okinawa islands, warning of waves up to 3 meters (nearly 10 feet) high. A 30-centimeter (nearly 1 foot) wave impacted Okinawa, the first tsunami observed there in 26 years, the agency said.

Several hours later, the US Tsunami Warning Center said the tsunami threat had “largely passed” but people in coastal areas should remain on alert.

All flights from Okinawa and Kagoshima prefectures were suspended following the tsunami warnings in the area, according to Japan Airlines.

Flights to and from Okinawa’s Naha airport resumed after the tsunami warning was downgraded to an advisory, airport spokesperson Hideaki Tsurudo told CNN.

This is a developing story and will be updated.