Australia will see the biggest gun buyback since the 1990s, after Prime Minister Anthony Albanese announced a national scheme on Friday.

Under the plan, similar to the 1996 one introduced by John Howard after the Port Arthur massacre, the states and territories will be responsible for collecting, processing and paying individuals for the firearms surrendered. The Australian Federal Police will be responsible for their destruction.

The cost of the scheme will be shared on a 50-50 basis.

Speaking after cabinet’s national security committee had met for the sixth time since Sunday’s massacre, Albanese told a news conference, “The terrible events at Bondi show we need to get more guns off our streets.

"We know that one of these terrorists held a firearm licence and had six guns in spite of living in the middle of Sydney’s suburbs there at Bonnyrigg. There’s no reason why someone in that situation needed that many guns.”

Albanese said there were more than four million firearms in Australia – more than at the time of the Port Arthur massacre. He expected hundreds of thousands of weapons to be collected.

The buyback is on top of a range of gun control measures being worked through by federal and state governments after a national cabinet meeting this week. The NSW government is bringing in measures at its special sitting of state parliament on Monday and Tuesday.

A spokesman for Opposition Leader Sussan Ley said the opposition supported “a sensible and proportionate examination of current gun laws” but needed to see actual details.

But Nationals Senate Leader Bridget McKenzie, who is a recreational shooter, went on the attack, accusing Albanese of seeking to cover his own failure to deal with Islamic extremism “by scapegoating innocent Australians”.

Saying there were about one million legal gun owners in Australia, McKenzie declared “we are not the problem. And we will not, and should not, stand by and take the blame.”

Australian Federal Police Commissioner Krissy Barrett looks on as Prime Minister Anthony Albanese speaks to media during a press conference at Parliament House in Canberra. Dominic Giannini/AAP

NSW Premier details crackdown on demonstrations

Meanwhile New South Wales Premier Chris Minns announced details of the measure to restrict demonstrations to be put to the special meeting of the state parliament.

The legislation will enable authorities to “restrict the authorisation of public assemblies in designated areas following a terrorist incident”.

When an incident is declared, the police commissioner or deputy, with the ministerial agreement, will be able to declare specific areas where public assemblies are restricted for a limited time.

A declaration may be made “where police determine public gatherings may be likely to cause a reasonable person to fear harassment, intimidation or violence or put community safety at risk,” the premier and Attorney-General, Michael Daley, said in a statement.

Once a declaration is made, no public assemblies in the area will be able to be authorised, including by a court.

“The powers are not designed to stop quiet reflection, prayer or peaceful gatherings that are not likely to cause fear or safety concerns,” the statement said.

Minns said: “This was a targeted terrorist attack that has shaken our state and devastated the Jewish community. The scale of harm demands a response that is decisive, sustained and unequivocal.

"Our first responsibility as a government is to protect people.

"There is a time for debate and protest in a democracy – but there is also a time for calm, care and unity. After an act of terror, public safety must come first.

"These powers are proportionate. They are not about suppressing views – they are about preventing intimidation, escalation and violence.”

In other initiatives, ISIS flags will be banned in NSW.

Seven men questioned in Sydney

Police in Liverpool on Thursday apprehended seven men in a spectacular action involving car ramming. The men had travelled in convoy from Victoria and police feared they might be planning a violent incident.

NSW Police Commissioner Mal Lanyon said on Friday police were looking at radical Islamist extremism as one of the ideologies behind the men.

The men were released late Friday. Lanyon said, “According to law we don’t believe we have sufficient evidence to detain the men”. He said they would continue to be monitored.

Day of mourning

Sunday has been declared a Day of Reflection to honour the victims of the Bondi massacre, in which 15 people were gunned down by two shooters, a father and son, and many more injured. One of the gunmen was killed; the second was wounded.