COTABATO, Philippines, July 24 (Xinhua) -- Three powerful tremors measuring between magnitude 7.3 and 7.4 hit the southern Philippines early Saturday, the United States Geological Survey reported, but no reports of damage or tsunami warning was issued.
The underwater quakes struck at a depth of between 576.3 and 616.7 kilometers, about 120 kilometers southwest of Cotabato, in Mindanao, said the US Geological Survey.
The quake was felt in the cities of Zamboanga, PaGadian and Koronadal but Officials were still determining if there were casualties or damages.
Yolly Andrias, a resident here, told Xinhua that they were still sleeping when the strong quake awoke them.
"Some of our Muslim neighbors fired their weapons to drive away bad spirits," she said.