Manila: A 6.8-magnitude earthquake struck off the Philippines on Saturday, officials said, damaging several buildings and injuring two people as panicked residents fled the coast following a tsunami warning.
US authorities warned of potential hazardous waves in the southern region of Mindanao and Indonesia after the quake hit at 4:23 am, but the tsunami alert was lifted less than two hours later.
Residents were jolted from their beds and ran onto the streets as the earthquake shook the area, leaving cracks in a hospital, two government buildings and a port, as well as triggering the collapse of at least one house and causing a brief power outage.
"The floor appeared to rise first before swaying violently from side to side. Then the lights went out," said Adrian Morallas, who was at work at the civil defence office in General Santos city at the time of the quake.
"I ducked and took cover under my desk in line with our disaster training, though it was very difficult to do that in the dark with the ground shaking."
Morallas said coastal communities near General Santos were told to evacuate as a precaution, though authorities do not know how many people actually left their homes.
The quake struck at a depth of 41 kilometres (25 miles) off Mindanao island, the US Geological Service said. The state-run Philippine Institute of Volcanology and Seismology gave a higher magnitude reading of 7.2. The epicentre was about 53 kilometres off Mindanao's south coast, it added.
"We do not expect major damage after this event," the institute's head Renato Solidum said on ABS-CBN television in Manila.
Morallas said two people were injured during the evacuations in the Mindanao coastal towns of Glan and Malapatan. One person was hit by a falling rock while a pregnant woman hurt herself when she fell.
The Philippines lies on the so-called Ring of Fire, a vast Pacific Ocean region where many of Earth's quakes and volcanic eruptions occur.
A 6.0-magnitude earthquake damaged dozens of houses on central Mindanao on April 12, while a trio of strong quakes battered buildings and caused panicked tourists to flee a popular resort near Manila on April 8.
A 6.5-magnitude quake killed eight people and left more than 250 injured outside the Mindanao city of Surigao in February, and another 5.9-magnitude tremor killed one person there last month.
Before Surigao, the last lethal earthquake to hit the country was a 7.1-magnitude tremor that left more than 220 people dead and destroyed historic churches when it struck the central islands in October 2013.