KEY POINTS:
• 50 confirmed dead, with victims ranging in age from 2 to older than 60
• 34 injured people remain in Christchurch Hospital, 12 are critical in intensive care
• Seven operating theatres in use, many patients will require multiple surgeries
• Girl, 4, remains in critical condition in Auckland's Starship Hospital
• Prime Minister Jacinda Ardern has placed a wreath at Kilbirnie mosque
• MI5 probe gunman's links to British extremists
• Australian-born accused gunman Brenton Tarrant a 'buffed up weirdo': associates
• Kiwis have already donated $5m for the victims' families

The Prime Minister's Office confirmed that it received a copy of a "manifesto" from the alleged Christchurch mosque massacre gunman less than 10 minutes before the attacks began on Friday — along with about 70 others recipients.

Most of the other recipients were media, both domestic and international, a spokesman for Prime Minister Jacinda Ardern said — although the New Zealand Herald was not listed among the recipients.

It had been framed as though events had occurred, he said.

"The mail was setting his reasons for doing it. He didn't say this is what I am about to do. There was no opportunity to stop it."

The email had gone to Ardern's generic address.

Other politicians on the mailing list were National leader Simon Bridges and Speaker Trevor Mallard.

Ardern would not be releasing its contents, the time it was received or even what was in the subject line.

"It does not set out what he was about to do. It was written as if it had occurred, to explain what obviously was about to play out."

Ardern last night flew back to Wellington from Christchurch and is expected to make a statement today.

The alleged gunman appeared to have been a lone wolf, say police who are piecing together New Zealand's worst act of terrorism.

Brenton Harrison Tarrant, a 28-year-old Australian national, smirked and flashed a White Power sign as he appeared manacled and barefoot in court yesterday.

He has been charged with murdering a man during Friday's busy prayers.

Police say more charges are likely.

A total of 49 people are confirmed dead. Health officials say 39 people remain in hospital, with 11 critical in intensive care. The youngest victim is 2. One child, 4, has been transferred to Starship children's hospital in Auckland.

Police allege Tarrant travelled between the Al Noor Mosque beside Hagley Park in central Christchurch and Linwood Mosque some 5km away within seven minutes.

After just 36 minutes dozens were dead and injured.

Tarrant was caught on Brougham St, dragged from a car by two police officers, and taken into custody.

Two others arrested during the chaos of the shooting aftermath have not yet been charged.

Tarrant had allegedly been living in Dunedin for two years, spending much of his time travelling overseas. He was not on any watch lists in New Zealand or Australia.

There was a large police presence at his Dunedin address yesterday, with bomb experts having scoured the property.

Police said five guns were used in the attacks, with two semi-automatic weapons, two shotguns, and a lever action firearm recovered from the scenes.

Ardern said Tarrant acquired a gun licence in November 2017.

She also confirmed that Tarrant had travelled the world with "sporadic periods of time spent in New Zealand".

Many tales of survival and missing loved ones, feared dead, are starting to emerge.

John Milne fought back tears telling how his "brave little soldier" son, 14-year-old Sayyad Milne, died at Al Noor Mosque.

The Year 10 Cashmere High School student was at the mosque he attended with his mother and friends every Friday.

"I've lost my little boy," his father said.

"[I'm] keeping it together and tears are helping. People are helping. Just by being here, it is helping.

"I remember him as my baby who I nearly lost when he was born. Such a struggle he's had throughout all his life.

"A brave little soldier. It's so hard ... to see him just gunned down by someone who didn't care about anyone or anything."

Al Noor elder Haji Daoud Nabi, a 71-year-old refugee from Afghanistan, died in what his sons describe as a "cowardly act".

"It's outrageous to me. Forty-nine people got killed — kids and grown-ups shot in the back while praying. It is a cowardly act," son Omar said.