MELBOURNE, Australia (AP) — A mass shooting in which 15 people were killed during a Hanukkah celebration at Sydney’s Bondi Beach was “a terrorist attack inspired by Islamic State,” Australia’s federal police commissioner Krissy Barrett said Tuesday.

The suspects were a father and son, aged 50 and 24, authorities have said. The older man was shot dead while his son was being treated at a hospital on Tuesday.

A news conference by political and law enforcement leaders on Tuesday was the first time officials confirmed their beliefs about the suspects' ideologies. Prime Minister Anthony Albanese said the remarks were based on evidence obtained, including “the presence of Islamic State flags in the vehicle that has been seized.”

There are 25 people still being treated in hospitals after Sunday’s massacre, 10 of them in critical condition. Three of them are patients in a children's hospital.

Also among them is a man who was captured on video appearing to tackle and disarm one assailant, before pointing the man’s weapon at him and then setting the gun on the ground.

Those killed ranged in age from 10 to 87 years old. They were attending a Hanukkah event at Australia's most famous beach Sunday when the gunshots rang out.

Albanese and the leaders of some of Australia's states have pledged to tighten the country's already strict gun laws in what would be the most sweeping reforms since a shooter killed 35 people in Port Arthur, Tasmania in 1996. Mass shootings in Australia have since been rare.

Officials divulged more information as public questions and anger grew on the third day following the attack about how the suspects were able to plan and enact it and whether Australian Jews had been sufficiently protected from rising antisemitism.

Albanese announced plans to further restrict access to guns, in part because it emerged the older suspect had amassed his cache of six weapons legally.

“The suspected murderers, callous in how they allegedly coordinated their attack, appeared to have no regard for the age or ableness of their victims,” said Barrett. “It appears the alleged killers were interested only in a quest for a death tally.”

The suspects traveled to the Philippines last month, said Mal Lanyon, the Police Commissioner for New South Wales state. Their reasons for the trip and where in the Philippines they went would be probed by investigators, Lanyon said.

He also confirmed that a vehicle removed from the scene, registered to the younger suspect, contained improvised explosive devices.

“I also confirm that it contained two homemade ISIS flags,” Lanyon said.