Prime Minister Justin Trudeau says he is outraged to hear that Canadian hostage John Ridsdel has been killed by terrorists in the Philippines, and is vowing to hunt down those responsible.

“This was an act of cold-blooded murder and responsibility rests solely with the terrorist group that took him hostage,” the prime minister said during a brief press conference in Alberta on Monday.

Trudeau said the safety of Canadians is a top priority and vowed to work with the Philippines and other allies “to pursue those responsible for this heinous act.”

The prime minister offered his condolences to the family and friends of Ridsdel.

He did not take questions, however, saying that commenting further could “compromise ongoing efforts or endanger the safety of the remaining hostages.”

Fellow Canadian Robert Hall, Norwegian Kjartan Sekkingstad and Filipino Marites Flor were also abducted from an upscale resort complex on a southern Philippine island in September, by Abu Sayyaf militants.

On April 15, a video emerged of Ridsdel, 68, and Hall asking the Canadian government to pay their ransom. In the video, the two warned that they would be beheaded if the ransom was not paid by 3 p.m. Monday. The captors were demanding about CAD $8 million per hostage.

On Monday, Philippine officials confirmed that the severed head of a Caucasian man was found in a plastic bag along a street in Jolo, a town in Sulu province.

Family, friends mourn loss

Sandy Hunter, who was best man at Ridsdel’s wedding, described his friend as “gregarious” and “outgoing.”

Hunter told CTV News Channel he will remember the good times they had together, whether sailing in France, or swimming, camping and drinking wine in the Rocky Mountains.

Ridsdel’s family issued a written statement, calling the killing a “senseless act of violence” that occurred “despite us doing everything within our power to bring him home.”

“John was a kind and gregarious person who touched everyone he knew with his enthusiasm and generosity,” the family said. “He loved life and lived it to the fullest with his family and friends at the centre.”

“He was loved by all his friends and adored by his daughters, sister, and extended family,” the statement went on.

Bob Rae tried to help

Bob Rae told CTV’s Power Play that he had known Ridsdel since 1966 when they attended the University of Toronto together.

The former interim Liberal leader said he had contacted Ridsdel’s sister and children as soon as he heard news of his capture, and was also involved in attempts to bring him home alive.

“Up until the last minute, the last few hours, a lot of efforts were being made to connect, to communicate,” Rae said. “Obviously there was talk of money involved, not by the Government of Canada or the Government of Norway, but certainly by the families,” he added.

Rae said that Canada has long had a “principled” policy of not getting directly involved in hostage negotiations or paying ransoms, in order to discourage kidnappings.

However, Rae said that “right up to the Prime Minister of Canada,” senior officials had been regularly involved in the crisis.

Rae added that there are still “a lot of conflicting reports about exactly what happened,” but that Ridsdel showed “an enormous amount of courage and dignity and honesty throughout the process.”

Rae said he will remember his friend as adventurous, gregarious man with an “insatiable curiosity,” which led him first to journalism and later to jobs in the mining and energy sectors.

Interim Conservative leader Rona Ambrose issued a statement Monday calling Ridsdel’s killing “shocking and saddening” and offering her condolences to his loved ones.

“Incidents like this should remind all of us that the threat of terrorism remains very real,” the statement went on. “We must stand with our allies in solidarity against terrorism, which remains the greatest challenge that the world faces today.”

With files from The Associated Press