Rescue workers carry a woman to an ambulance after she became dizzy following an earthquake hit Manila, Philippines, April 22, 2019. AP

Manila, Philippines -- A strong earthquake in the north Philippines on Monday trapped some people in a collapsed building, damaged an airport terminal and knocked out power in at least one province, officials said. Gov. Lilia Pineda of Pampanga province, north of Manila, told DZMM radio that about 20 people were rescued, some with injuries, from the small building which collapsed in Porac town when the 6.1 magnitude quake jolted the capital and outlying provinces on the main northern island of Luzon.

Among those trapped were customers and employees of a grocery on the building's ground floor, Pineda said. She said at least three people perished in the collapsed building, but Porac Mayor Carling dela Cruz told DZMM radio that they were only injured and were taken to a hospital. Rescuers were struggling to extricate people from the building in the dark because the quake toppled electrical posts and knocked out power in the area, she said.

"There are still some people inside but they (the rescuers) can't lift the debris that crashed down," Pineda said, appealing for cranes to help save the trapped people.

Get Breaking News Delivered to Your Inbox

Pineda said she had received reports that the quake left at least eight people dead in her province, a rice-growing agricultural region, but could not provide details. Cellphone signals were erratic in some areas.

The quake also damaged an airport terminal at Clark freeport, a former U.S. Air Force base, and an old Roman Catholic church in Pampanga, and caused cracks in highways and bridges, Pineda and other officials said.

Clark airport was closed temporarily because of damaged check-in counters, ceilings and parts of the departure area, airport official Jaime Melo said, adding that seven people were slightly injured and more than 100 flights were canceled.

Wearing protective helmets, employees evacuate their office building following an earthquake in Manila, Philippines, April 22, 2019. AP

Renato Solidum, who heads the Philippine Institute of Volcanology and Seismology, said the late afternoon quake was centered near the northwestern town of Castillejos in Zambales province. Dozens of aftershocks were recorded.

After the earthquake struck the capital, Manila, hundreds of office workers dashed out of buildings in panic, some wearing hard hats, and residents ran out of houses.

The Philippines, one of the world's most disaster-prone countries, has frequent earthquakes and volcanic eruptions because of its location on the so-called Pacific "Ring of Fire," a seismically active arc of volcanoes and fault lines in the Pacific Basin. A magnitude 7.7 quake killed nearly 2,000 people in the northern Philippines in 1990.