Philippines TV footage shows the scale of devastation in the wake of Tuesday's 7.2 magnitude quake.
Initial reports said at least six people were killed as buildings collapsed on the islands of Cebu and Bohol, both popular with tourists.
Later reports said the number was at least 20.
The total number of casualties could not be immediately confirmed.
Several buildings have been destroyed or badly damaged.
These still images from Cebu give some idea of the power of the quake.
Cars lie crushed beneath the wreckage of nearby buildings.
This church lost its bell tower.
The U.S. Geological Survey put the quake at a depth of about 56 kilometres.
No tsunami warnings were issued, but the Philippine Coastguard temporarily suspended sea travel in the region and some flights were cancelled.