- President Benigno Aquino vows to "smash" militant group
- "This was an act of cold-blooded murder," Canada's prime minister says
- John Ridsdel was one of four people taken hostage in September
- Islamist militant group Abu Sayyaf released videos that purported to show the hostages
(CNN)The President of the Philippines said he is "appalled" by the murder of Canadian citizen John Ridsdel by ISIS-aligned militants in the south of the country.