At least eight people have been killed after a magnitude 6.1 earthquake struck the Philippines' main island of Luzon, while officials fear dozens could be trapped in the rubble of a collapsed commercial building.
The quake hit 60km northwest of the capital Manila on Monday afternoon, disrupting air, rail and road transport and causing some damage to buildings and infrastructure.
The province of Pampanga was worst hit. Eight people were killed and about 20 injured, provincial governor Lilia Pineda said.
Rescuers were using heavy duty equipment and search dogs to try to reach people trapped after a four-storey building went down, crushing a ground-floor supermarket, she said.
"They can be heard crying in pain," Pineda said of those trapped. "It won't be easy to rescue them."
Pampanga's international airport at Clark, a former US military base, was closed and scores of flights were cancelled after damage to parts of the facility.
Large cracks appeared on provincial roads and electricity poles were felled.
Rescue teams in Manila were preparing to reinforce efforts to reach people trapped in Pampanga.
The government urged people to be calm as rumours of greater death and destruction gained traction online.
"We urge them to refrain from spreading disinformation in social media that may cause undue alarm, panic and stress," presidential spokesman Salvador Panelo said.
The earthquake hit shortly after 5pm local time in Manila and caused tall buildings to sway for several minutes in the main business districts.
"We got nervous, we got dizzy. I ran downstairs with three kids," domestic worker Arlene Puno said.
Elevated rail services were halted and workers were evacuated from offices and condominiums, sending a flood of people onto footpaths and into bus queues and adding more chaos to Manila's already congested roads.