Australia is in the middle of a national firearms amnesty program, with residents urged to voluntarily turn in unregistered guns. 

The government says the program is designed to reduce the number of illegal weapons, including those being used in an increasing number of terror attacks.

Australian Justice Minister Michael Keenan said, "We are living in a time when our national security environment has deteriorated. Unfortunately, we have seen, through terror attacks in Australia that illegal guns had been used."

That includes the 2014 Sydney siege, where three people including the gunman were killed. The government estimates there are nearly a quarter of a million illegal guns currently in circulation. 

The country’s first national firearms amnesty was launched almost two decades ago by former Australian Prime Minister John Howard. That buy-back scheme netted more than 600,000 guns, and came as a response to the 1996 Port Arthur Massacre, where a lone gunman killed 35 people in Tasmania. Australia's worst mass murder also prompted a tightening of the country’s gun laws, still regarded as some of the toughest in the world. 

David Shoebridge is a New South Wales member of parliament. He says some of those laws have been watered down over the years by the gun lobby, and he estimates there will soon be up to one million registered guns in his state alone. 

"Any gun amnesty that actually gets firearms out of the community, has them surrendered and delivered to police is going to be a step forward for community safety.”

Michael Kennedy is a professor at Western Sydney University and a former police detective. He doubts a national gun amnesty will have any impact on the number of terrorist attacks. However, he says it is another example of an approach to the issue in Australia that’s helped to reduce the kind of debate over gun laws seen in other countries. 

"It’s a good opportunity for the police to engage with the public on a consenting and a mutual understanding basis and engage with the public when normally when the police engage with the public it’s from a coercion perspective," he added.