The quake struck at sea 71 kilometres (44 miles) off Negros island's coast at 1:21pm (0521 GMT), with fairly strong ground shaking across the island's west coast, the Philippine Institute of Volcanology and Seismology said.

The ground disturbance was fairly shallow, and the institute expects damage and aftershocks, it said in a bulletin.

However, the civil defence office in the region had no immediate reports of damage or casualties, said Eligio Calaor, the regional office's operations chief.