SYDNEY — The Australian government will launch a gun buyback program to take hundreds of thousands of firearms off the streets, Prime Minister Anthony Albanese said Friday, following a shooting rampage at a Jewish holiday festival that killed 15 people.

Speaking at a news conference, Albanese also declared that Sunday will be a national day of reflection when Australians will pause for a minute of silence to honor the victims of the attack at a popular beach in Sydney.

The focus on firearms comes as authorities have said the two gunmen accused of carrying out the attack, a father and son, were motivated by the Islamic State group. The terrorist group has posted a video claiming credit for inspiring the attack, Albanese said.

One of the gunmen held a firearm license and had six guns “in spite of living in the middle of Sydney’s suburbs,” Albanese said. “There’s no reason why someone in that situation needed that many guns.”

The government has said that it will tighten laws around gun ownership, and new measures are under consideration that could include a cap on the number of firearms that can be owned by an individual, and tighter limits on the types of guns permitted.

Australia launched an even larger gun buyback scheme after a 1996 mass shooting that killed 35 people on the southern island of Tasmania. By some estimates, that program melted down as many as 1 million guns.

On Sunday, Australians will be encouraged to observe the moment of silence and light a candle at 6:47 p.m., exactly one week after the attack, Albanese said. Flags across the state of New South Wales and on Australian government buildings nationwide will be flown at half-staff. A national day of mourning will also be held in January, he added.

On Friday, Bondi Beach park in Sydney, where the shooters killed Hanukkah festival participants, reopened to the public as funerals for the victims continued.

The authorities are continuing to investigate the shooters, who they believe acted alone.