New Zealanders today marked one week since a mass shooting killed 50 Muslim worshippers in the South Island city of Christchurch, holding nationwide prayers and wearing headscarves to show their support for the devastated community.

Prime Minister Jacinda Ardern joined an estimated 5,000 people standing quietly at Hagley Park in front of the Al Noor mosque, where most of the victims died.

The Muslim call to prayer at 1.30pm local time (8.30am in Malaysia) was broadcast nationally, followed by two minutes of silence.

Ardern, who swiftly denounced the attack as terrorism, yesterday announced a ban on military-style semi-automatic and assault rifles under tough new gun laws.

Most victims of New Zealand's worst mass shooting were migrants or refugees from countries such as Pakistan, India, Malaysia, Indonesia, Turkey, Somalia, Afghanistan and Bangladesh.

The #headscarfforharmony movement, launched by an Auckland doctor, encouraged people to wear headscarves on Friday to show their support for the Muslim community.

Robyn Molony, 65, was with a group of friends wearing headscarves at Hagley Park, where they walked daily.

“We are wearing headscarves showing our support, love and solidarity, and hope that by everybody doing this will demonstrate to Muslim women... that they are one with us," she said.

Images of a grieving Ardern wearing a black headscarf as she visited families of the victims a day after the attacks were broadcast around the world.

Muslims account for just over one percent of New Zealand's population, most of whom were born overseas.

New Zealand mourns

“It’s good that people acknowledge what has happened here," said Mark Rangi, 59, who was praying in Al Noor mosque last Friday when the shooter walked in.

Rangi, who came to the service on crutches, said he was hit in the leg with bullet fragments and won’t pray because he can’t get down with his stitches.

"It’s good that the whole Christchurch community has come down and says this isn’t right.”

Authorities have estimated more than 2,000 people would be at the prayers and the burials during the day.

"We're not moving on. This grieving is going to take a long time," said 52-year-old Christchurch resident Bell Sibly, who wore a headscarf to show her support. "But what he's done, he was hoping to divide us, and instead, he's brought us all

together in one big hug."

Residents of Christchurch are still recovering from a devastating earthquake that hit the city in 2011, killing 185 and injured thousands.

"Since the earthquakes, we’ve gone through a lot as a city and we’re a lot more caring and looking out for one another,” said James Sheehan, 62.

Security high

Armed police have been guarding mosques around New Zealand since the attacks and police said there would be a "heightened presence" today to reassure those attending weekly prayers.

Officers dotted around Christchurch wore green ribbons pinned to their chests as a sign of peace and solidarity.

Candlelight vigils continued across the country until late last night, while volunteers prepared the bodies of the deceased for a mass burial that is expected after the prayers.

“All the bodies are washed. We finished around 1.30am this morning. It was our duty. After we finished there was a lot of emotion, people were crying and hugging," said a body washer in Christchurch who gave his name as Mo.

Australian Brenton Tarrant, 28, a suspected white supremacist, has been charged with one murder following the attack and has been remanded without a plea.

The media reported police had initially named a survivor of the attack as the victim, requiring a change to his charge sheet.

Tarrant is due back in court on April 5, when police said he would likely face more charges.

- Reuters