The Muslim call to prayer rang out across New Zealand today followed by two minutes of silence nationwide to mark a week since a white supremacist shot dead 50 people at two mosques in the city of Christchurch.

As the call was broadcast around the country, thousands of people - including Prime Minister Jacinda Ardern - stood silently in a park opposite the mosque where the killings began, as the country came to a standstill.

The massacre has shocked a nation known for its tolerance.

It has prompted Kiwis to respond with vigils and performances of the traditional Maori haka dance, and to form lines behind Muslims to symbolically protect them while they pray.

A muezzin in white skullcap issued the call to regular Friday prayer with chants of "Allahu Akhbar" (God is greatest) as thousands listened in Christchurch's Hagley Park across from the Al Noor Mosque.

The country then fell silent for two minutes, with public gatherings in Auckland, Wellington and other cities.

In neighbouring Australia, people stopped in the streets and in shops to mark the moment.

Al Noor imam Gamal Fouda denounced hatred, and praised the sense of Kiwi togetherness that the killings have sparked.

"I look out and I see the love and compassion in the eyes of thousands of fellow New Zealanders and human beings from across the globe," he said.

"This terrorist sought to tear our nation apart with an evil ideology that has torn the world apart. But, instead, we have shown that New Zealand is unbreakable."

Many women in attendance wore headscarves in solidarity with New Zealand's Muslim community.

New Zealand's Prime Minister Jacinda Ardern (C) arrives to attend islamic prayers

Kirsty Wilkinson joined the throng at Hagley Park along with two female friends, all in make-shift hijabs.

"I personally am doing this to knock down my walls of personal oblivion to the terror Muslim people feel every day, worrying about their safety," Ms Wilkinson told AFP before the prayers began.

"I can take my scarf off if I feel afraid. They cannot.

"The message I want to send is that hate cannot win. We are all just people. What happened is not okay."

The gunman killed 50 men, women and children - the victims aged between three and 77 years old - and left dozens injured in an attack that he livestreamed on social media, sparking global revulsion.

The sombre ceremonies came a day after Ms Ardern announced an immediate ban on assault rifles and military-style semi-automatic weapons, making good on a pledge to rid the country of the kinds of weapons used in the attack.

The move triggered renewed calls from leading US politicians for a similar response in the United States, which has suffered a stream of mass shootings but left gun reform untouched.

In Christchurch, police and tradesmen had been working intensively in the hope of repairing the Al Noor mosque's bullet-scarred and blood-spattered interior ahead of afternoon prayers.

But authorities late last night announced that prayers would be held in the park instead.

The national mourning and moment of silence were broadcast on television networks, radio and across multiple local media websites.

"We are so happy that this prayer will be broadcast to the entire world so that everyone can be part of it," Mustafa Farouk, president of the Federation of Islamic Associations of New Zealand, said in a statement announcing the prayer session.

Burials of victims resume today.

Kate Mills Workman, a student from Wellington, posted a selfie on Twitter showing her wearing a green headscarf.

"Obviously this is all spurred on by the terrible tragedy in Christchurch but it's also a way of showing that any form of harassment or bigotry based on a symbol of religion is never okay," she said.

"As New Zealanders, we have to make a really strong stand."