New Zealand will tighten gun laws in the wake of its worst modern-day massacre, the government said yesterday, as it emerged that the white supremacist accused of carrying out the killings at two mosques will represent himself in court.

Prime Minister Jacinda Ardern said her coalition was unified on the need to reduce the availability of the kind of weapons used by Brenton Tarrant as he went room to room shooting Muslims gathered for Friday prayers.

"We have made a decision as a cabinet, we are unified," she said, flanked by her coalition partner and deputy prime minister, Winston Peters.

Peters, whose New Zealand First party has previously opposed changes, said he backed the prime minister fully.

"The reality is that after one pm on Friday our world changed forever, and so will our laws," he said.

Ardern, the youthful premier who has become the face of the nation's tragedy, said there would be an inquiry into the horrifying attack, as questions swirl over whether intelligence agencies should have spotted warning signs.

The role of social media has also come under the spotlight, after the gunman live-streamed his rampage on Facebook.

A teenager, whose name cannot be published, appeared in court yesterday and charged with distributing that footage.

Meanwhile, police launched a probe into a bomb hoax that forced an hours-long closure of the airport in Dunedin on Sunday, where Tarrant lived.

Grief continued to wash across the nation yesterday, with New Zealanders of all stripes gathering to express revulsion over the killings -- and a unified front against racial hatred.

Family and friends outside Al Noor mosque -- the scene of the largest massacre -- held a sunset prayer session, with their mournful cries echoing through a park as locals looked on.

"It just happened to be the time of our evening prayer. Anywhere you are, you can just pray anywhere," Saiyad Raza, who had travelled from Auckland to bury his cousin who died in the shootings, told AFP.

Earlier, a Maori cleansing ceremony was performed at the mosque, bringing together indigenous Kiwis, Muslim leaders and local officials.

Dozens of students then paid their respects, with many coming together for a haka -- a traditional Maori ceremonial dance that has been performed by groups across New Zealand in the wake of killings.

And in Auckland, students at Orewa College gathered to form a heart and the message "Kia Kaha" -- "stay strong" in Maori.

'NOTHING EXTRAORDINARY'

The organisers of New Zealand's largest gun show -- the Kumeu Militaria Show, near Auckland -- announced yesterday they had cancelled the event in the wake of the massacre and because of "elevated security risks".

Despite having tightened the rules in the 1990s after the last mass shooting, New Zealand has relatively permissive gun laws, with licences granted to nearly every applicant.

David Tipple, the managing director of Gun City, whose online store sold Tarrant four weapons, said he felt no responsibility for the killings.

"We detected nothing extraordinary about this licence holder," he told reporters.

Tarrant, who appeared in court on Saturday charged with murder, yesterday sacked his state-appointed lawyer.

Richard Peters, who represented the alleged killer during the hearing, told AFP the 28-year-old "wants to be self-represented in this case".

"The way he presented was rational and someone who was not suffering any mental disability. He seemed to understand what was going on," Peters said.

Under New Zealand law, if Tarrant pleads not guilty his case would normally go to trial, raising the possibility that he could face survivors and victims' families in court.

Mustafa Farouk, president of the Federation of Islamic Associations of New Zealand, told reporters he had faith in the system.

"As a community, we would like that person to go through the process, the due process, and to be given all his rights," he said.

"We believe in the justice system here and we know it will do what is right."

But, he cautioned, the attitudes that gave rise to the killing -- documented in a rambling, racist screed released online minutes before the attacks began -- must be tackled.

"This rise in hatred... by people who call themselves right-wing, whether smaller groups or through reckless politicians, should not be allowed to continue."

DIGGING GRAVES

Frustrated families of the 50 victims were still waiting yesterday for the release of the bodies of their loved ones, as officials worked their way through a painstaking investigation.

Dozens of graves were being dug in readiness for that release, which Police Deputy Commissioner Wally Haumaha said would hopefully happen soon.

"The process has been highly emotional and stressful for all... as in accordance with Islamic faith the families have wanted the bodies to be returned as soon as possible," he said.

"We have burial expert teams in place ready to receive the bodies at a point in time."

The dead span generations, aged between three and 77, according to a list circulated among relatives.

Some victims came from the neighbourhood, others from as far afield as Egypt. At least two of the dead came from the same family -- a father and son.

Delhi said Sunday that five of its nationals were killed, while Pakistan said nine of its citizens were among the dead, including one man who died trying to rush Tarrant.

Authorities said 31 people remained in hospital, nine in critical condition.