Open this photo in gallery: Call center employees gather outside their office building after earthquake tremors at Cebu in central Philippines on Tuesday.ALAN TANGCAWAN/AFP/Getty Images

An offshore earthquake of magnitude 6.9 collapsed walls of houses and buildings late Tuesday in a central Philippine province, killing at least 20 people, injuring many others and sending residents scrambling out of homes into darkness as the intense shaking cut off power, officials said.

The epicenter of the earthquake, which was set off by a local fault, was about 17 kilometre