MANILA: A powerful earthquake was felt in the Philippine capital Manila on Thursday, causing office workers to rush out of buildings, but authorities said there were no immediate reports of damage.

The Philippine Institute of Volcanology and Seismology said the quake struck in the ocean about 100 kilometres (62 miles) southwest of Manila at 1:29 pm (0529 GMT) with a magnitude of 6.0.

The US Geological Survey said the quake had a magnitude of 6.1, with its epicentre located 137 kilometres (85 miles) southwest of Manila and at a depth of 72 kilometres.

Office workers rushed out of their buildings in Manila's Makati financial district, while government employees across town hid under their tables, radio reports said.

"It felt very strong. We're on the 10th floor of the building, and we felt we were being rocked for about a minute," said Elaine Francisco, an executive with an advertising company in Makati.

"We opened the door and prepared to go out, but it ended just when about we were going to go."

Francisco said others in the lower floors of the building fled their offices, but returned when it became clear the structure was safe.

Government seismology institute chief Renato Solidum said the quake was felt in varying intensities in suburbs around the capital of 12 million people as well as in nearby provinces.

But more than an hour after the quake, Manila's Office of Civil Defence and police said there had not yet been any reports of damage.