A strong 6.4-magnitude earthquake rocked the northern Philippines and southern Taiwan on Sunday, the US Geological Survey said.
The quake struck at a shallow depth of 22 kilometres (14 miles) under the seabed in the Philippines' Batan Islands region at 0157 GMT, it said.
There were no immediate reports of any casualties or damage and no tsunami warning was issued.
Taiwan's Central Weather Bureau measured the quake at 6.8 on the Richter scale and located it a depth of 46 kilometres.
The Philippine Institute of Volcanology and Seismology said the quake had a magnitude of 6.3 with an epicentre about 76 kilometres west of the Batan town of Basco.
The quake was felt strongly in Basco but was barely noticeable in the northern provinces of the Philippines' main island of Luzon, the institute said, adding that aftershocks were expected.
It was also felt in southern counties of Taiwan.