MANILA, Philippines — A strong earthquake set off landslides and damaged buildings in the northern Philippines in Wednesday, killing at least four people and injuring dozens. In the capital, hospital patients were evacuated and terrified people rushed outdoors.

The 7-magnitude quake was centered in a mountainous area of Abra province, said Renato Solidum, the head of the Philippine Institute of Volcanology and Seismology, who described the midmorning shaking as a major earthquake.

“The ground shook like I was on a swing and the lights suddenly went out. We rushed out of the office, and I heard screams and some of my companions were in tears,” said Michael Brillantes, a safety officer of the Abra town of Lagangilang, near the epicenter.

“It was the most powerful quake I’ve felt and I thought the ground would open up,” Brillantes told The Associated Press by cellphone.

At least four people died mostly in collapsed structures, including a villager hit by falling cement slabs in his house in Abra, where at least 25 others were injured. In Benguet province, a worker was pinned to death after a small building that was under construction collapsed in the strawberry-growing mountain town of La Trinidad.

Many houses and buildings had cracked walls, including some that collapsed in Abra, where President Ferdinand Marcos Jr., who took office less than a month ago, planned to travel Thursday to meet victims and local officials.

Marcos Jr. told a news conference he was in his office at the riverside Malacanang presidential palace complex when the chandeliers began swaying and making clanking sounds. “It was very strong,” he said of the ground shaking.

In a chilling near-death experience, Filipino photojournalist Harley Palangchao and companions were traveling downhill in two vans in Mountain Province when they suddenly heard thunder-like thuds and saw an avalanche of boulders as big as cars raining down just ahead of them from a towering mountain.

Amid screams of his companions in their van to “back up, back up!” the 44-year-old father of three raised his camera in the front seat and snapped what he feared could be the final pictures of his life. The van in front of them was grazed by a boulder, injuring one, but he and others in the second van drove backward fast enough and escaped unscathed.

“I was thinking there should be at least a record if something happened to us,” Palangchao told the AP. “It was a horrific experience.”

The Red Cross issued a picture of a three-story building precariously leaning toward a debris-covered road in Abra. A video taken by a panicking witness showed parts of an old stone church tower peeling off and falling in a cloud of dust on a hilltop.

Patients, some in wheelchairs, and medical personnel were evacuated from at least two hospitals in Manila, about 300 kilometers (200 miles) south of Lagangilang, but were later told to return after engineers found only a few minor cracks on walls.

The quake’s strength was lowered from the initial 7.3 magnitude after further analysis. The quake was set off by movement in a local fault at a depth of 17 kilometers (10 miles), the institute said, adding it expected damage and more aftershocks.

The Philippines lies along the Pacific “Ring of Fire,” an arc of faults around the Pacific Ocean where most of the world’s earthquakes occur. It is also lashed by about 20 typhoons and tropical storms each year, making it one of the world’s most disaster-prone countries.

A magnitude 7.7 quake killed nearly 2,000 people in the northern Philippines in 1990.