It was four Russian tourists who were out diving together with an instructor near Batangas on the main island of Luzon on Thursday, the coast guard tells news agencies.
But strong currents pulled the group apart, and when the authorities were alerted, a search operation was launched.
One of the Russians, 39 years old, was recovered dead from the water, apparently drowned. But even more gruesome remains were found. On another body that was found, several parts were missing and a number of sharks circled nearby during the recovery.
The coast guard's district chief Airland Lapitan describes it as the man, a 29-year-old, being attacked right before the rescue team's eyes, and literally being dragged around in a shark's jaws.
In some way, they managed to get him loose, says Lapitan to the news agency AP.
Whether he had first drowned and then been attacked could not be immediately determined.
The diving instructor and the two other Russians had by then been able to return to their boat unharmed.
It is rare for people to be attacked by sharks in the Philippines. According to a global database, this is the first time in at least a year, writes news agency AFP.
