Christchurch, New Zealand -- New Zealand Prime Minister Jacinda Ardern announced an immediate ban Thursday on sales of "military-style" semi-automatic firearms and high-capacity magazines in the wake of a terrorist attack on two mosques in Christchurch that killed 50 worshippers. Ardern said the sales ban was effective immediately to prevent stockpiling and would be followed by a complete ban on the weapons after new laws were rushed through.

She said people could hand over their guns under an amnesty while officials develop a formal buyback scheme, which could cost up to 200 million New Zealand dollars ($140 million).

The man charged in the mosque attacks had purchased his weapons legally using a standard firearms license and enhanced their capacity by using 30-round magazines "done easily through a simple online purchase," Ardern said.

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"Every semi-automatic weapon used in the terrorist attack on Friday will be banned," she said.

The ban includes any semi-automatic guns or shotguns that are capable of being used with a detachable magazine that holds more than five rounds. It also extends to accessories used to convert guns into what the government called "military-style" weapons.

It does not include semi-automatic .22 caliber or smaller guns that hold up to 10 rounds or semi-automatic and pump-action shotguns with non-detachable magazines that hold up to five rounds. The guns not banned are commonly used by farmers and hunters.

The government said the police and military would be exempt as would businesses carrying out professional pest control. Access for international shooting competitions would also be considered.

Ardern said Thursday the government was working on a large-scale buy-back plan to encourage owners of now-banned weapons to surrender them. She did not say what would happen to those who violate the law.

She also said she and the Cabinet would work through legal exemptions to the ban, such as for farmers needing to cull their herds but said any exemptions would be "tightly regulated."

"For other dealers, sales should essentially now cease. My expectation is that these weapons will now be returned to your suppliers and never enter into the New Zealand market again," she said.

Major gun retailer reacts

After Ardern's announcement, one of New Zealand's largest gun retailers, Hunting & Fishing New Zealand, reiterated its support of "any government measure to permanently ban such weapons."

"While we have sold them in the past to a small number of customers, last week's events have forced a reconsideration that has led us to believe such weapons of war have no place in our business -- or our country," chief executive Darren Jacobs said in a statement.

Regardless of the ban, the company would no longer stock any assault-style firearms of any category and would also stop selling firearms online, he said.

Although the exact weapons used in the mosque attacks have not been made public, images of them posted by the gunman show at least one of them to be a semi-automatic rifle similar to an AR-15 that is widely available in New Zealand. Semi-automatic refers to a firearm's ability to self-load, not only firing a bullet with each trigger pull, but also reloading and making the firearm capable of firing again.

Many different types of firearms, from pistols to rifles and shotguns, can be semi-automatic. Semi-automatic rifles like the AR-15 can often be modified with aftermarket parts, or accessories, to fire in fully automatic mode and instructions can often be found on the internet.

Polly Collins, 64, of Christchurch, was thrilled to hear of Ardern's announcement as she visited a flower memorial for the victims.

"The prime minister is amazing," she said. "It's not like in America, where they have all these things and then they go 'Oh yeah, we'll deal with the gun laws,' and nothing's done."

All mosque victims identified

Ardern's announcement comes as authorities announced that all 50 bodies from the attacks were formally identified and families were burying their loved ones.

At least nine funerals took place Thursday, including for a teenager, a youth soccer coach and a Muslim convert who loved connecting with other women at the mosque.

At the cemetery, solemn farewells continued for Cashmere High School student Sayyad Ahmad Milne, 14, who was known as an outgoing boy and the school's futsal goalkeeper. Tariq Rashid Omar, 24, graduated from the same school, played soccer in the summer and was a beloved coach of several youth teams and was also buried Thursday.

In a post on Facebook, Christchurch United Football Club Academy Director Colin Williamson described Omar as "a beautiful human being with a tremendous heart and love for coaching."

Linda Armstrong, 64, a third-generation New Zealander who converted to Islam in her 50s, was also buried, as were Hussein Mohamed Khalil Moustafa, 70, Matiullah Safi, 55, and Haji Mohammed Daoud Nabi.

Police Commissioner Mike Bush said all 50 victims had been identified as of Thursday and their families were being notified. Investigators also were trying to conclude their work at the two mosques.

"We are working to restore them in a way that is absolutely respectful," he said.

Meanwhile, preparations were underway for a massive Friday prayer service to be led by the imam of one of the mosques where worshippers were killed. Imam Gamal Fouda said he expected 3,000 to 4,000 people at the prayer service, including many who have come from abroad.

Hate "will never be successful"

One member of Christchurch's Muslim community, Ambreen Rashid, said she still has faith. But it would be more than understandable if she did cry: Her husband and son were both among the 50 killed.

"I have love in my heart. So I'm happy and contented. You can't see me crying," she said.

When the gunman began his hate-fueled rampage in Christchurch, Ambreen's son Talha, 21, was inside the Al Noor mosque, praying.

"Talha was a gem. He was such a kind, gentle person, always pretty helpful," Ambreen told CBS News' Ben Tracy. "He will live forever because beautiful things never die."

She also lost her husband of 22 years, Naeem, who reportedly tried to stop the gunman. "He had a strong faith and he had love. So it made him so strong that he could confront a man with a weapon."

Rashid has found strength in something she saw at an ever-growing memorial in Christchurch. There's a sign on the fence with just eight words: Birthplace: Earth; race: human; politics: freedom; religion: love.

"Those people with hate, they will never be successful. My son, my husband and all those people who gave up their lives, they have just brought all the humans together," Ambreen said.

Suspect due back in court

An Australian white supremacist, Brenton Harrison Tarrant, was arrested by police who ran him off the road while he was believed to be on his way to a third target. He had livestreamed the attack on Facebook and said in his manifesto he planned to attack three mosques.

Tarrant, 28, is next scheduled to appear in court on April 5, and Bush said investigations into him were continuing. Police have said they are certain Tarrant was the only gunman but are still investigating whether he had support.

As the investigation continues into the attack, Ardern has also said an inquiry would look into intelligence and security services' failures to detect the risk from the attacker or his plans.