Jacinda Ardern has said her cabinet is “completely unified” in reforming gun legislation in the wake of the Christchurch terror attack but emerged from a meeting with ministers without concrete proposals to change firearms laws.

The New Zealand prime minister had been expected to announce measures such as a ban on semi-automatic rifles, a plan that was flagged by her attorney general, David Parker, one day after the massacre in which 50 people died.

However, after emerging from a long cabinet meeting Ardern said her team would take the rest of the week to work out the details after agreeing to make changes “in principle”. The agreement had been reached just 72 hours after the attack, she said, comparing her response time to that of the Australian government after the Port Arthur massacre.

“Within 10 days of this horrific act of terrorism we will have announced reforms which will, I believe, make our community safer,” Ardern said at news conference.

“These aren’t simple areas of law. So that’s simply what we’ll be taking the time to get right,” she said.

Hours before Ardern’s appearance, the country’s biggest online auction site, TradeMe, banned semi-automatics and “associated” accessories, saying “it is clear public sentiment has changed”.

On Monday, an 18-year-old man was charged with distributing a live stream of the mass shooting and was denied bail. He reportedly posted a photograph of one of the mosques attacked with the message “target acquired” among other chat messages “inciting extreme violence”, the New Zealand Herald reported. His name has been suppressed and he is due back in court next month.

Previous efforts to change gun laws failed in 2005, 2012 and 2017. Deputy prime minister Winston Peters, whose NZ First party has previously not supported recommendations to restrict gun laws, said on Monday that, after Friday’s attacks: “Our world changed forever and so will some of our laws.”

On Monday, Ardern also said an inquiry would be launched into the events leading up to the shootings, including the suspect’s travel and social media use and whether concerns voiced by Muslim citizens had been taken seriously.

She urged gun owners to hand in their weapons, and advised anyone considering buying a gun to wait a few days to get some certainty around the laws before investing.

Earlier, David Tipple, the managing director of retailer Gun City, confirmed his company had sold the suspect four weapons – but the gun he used to carry out the mosque shootings was not one of them. Tipple would not be drawn on his views on gun control, but intimated guns were not the issue.

“I had my grandson say to me: ‘Granddad, why do people think the guns were the problem? The guy was crazy.’ He is six years old,” Tipple told a media conference.

Earlier on Monday, TradeMe banned the sale of all semi-automatic weapons and “associated” accessories. Its CEO, Jon Macdonald, said the ban would be reviewed once there was more clarity on future gun laws.

He said: “We’ve had a lot of contact from Kiwis over the weekend about this issue, and many felt that we should stop the sale of these items in the wake of this attack. We’ve listened to these sentiments and we’ve put this ban in place while we await clear direction from the government.”

The focus fell on semi-automatic military-style rifles with high-capacity magazines at the weekend after Ardern said it was believed the weapons used in the attack had been modified and that loopholes that allow such modifications would be closed.

Gun control experts told the Guardian such weapons can be easily converted into a military-style semi-automatic rifle using a high-capacity magazine, the sale of which is not regulated in New Zealand.

The attorney general said such rifles would be banned after it emerged the suspect in Friday’s attack used five guns, two of which were semi-automatics.

Police commissioner Mike Bush has urged locals to return to their normal lives, to remain “vigilant” but to reject fear and reclaim the streets of their city.

But on Monday it was hard for residents to embrace routine and normality as diggers fanned out around the city to prepare 50 graves. Experts in Islamic burial rights also converged on the city.

Raf Manji, a Christchurch city councillor and a Muslim, told Nine to Noon: “There’s a sense of weariness. It’s been a very long, hard weekend, and I think people will be a little bit washed out and will be pleased to be back in their places of work and study, and congregate with their friends and colleagues.

The Guardian