A strong earthquake jolted the southern Philippines early Thursday, but there were no immediate reports of serious damage or casualties, seismologists said.
The magnitude-5.7 quake was centered at sea, about 140 kilometers (85 miles) southwest of Isulan town in Sultan Kudarat province, or about 1,000 kilometers (620 miles) southeast of Manila, Erlinton Olavere of the Philippine Institute of Volcanology and Seismology said.
The earthquake, which struck at 12:53 a.m. (1653 GMT Wednesday), was also felt in the southern Philippine cities of Cotabato and Pagadian, and the towns of Palimbang and Takurong, he added.
Small aftershocks were recorded by the institute, but were too weak to be felt by residents, Olavere said.
The Hong Kong Observatory put the magnitude of the quake at 6.2, but Olavere said the Philippine institute's instruments showed a magnitude of 5.7.
The Philippines is in the Pacific "Ring of Fire," where earthquakes and volcanic activity are common. A magnitude-7.7 earthquake in 1990 killed nearly 2,000 people on the main northern island of Luzon, AP reported. V.A.