The families of 50 worshipers who were gunned down in a terror attack at a mosque in Christchurch waited anxiously late Sunday for the return of their loved ones as had been agreed by New Zealand's prime minister.

The initial number looks set to be small, but it was expected that all bodies would be returned to relatives by Wednesday, Jacinda Ardern said at a news conference in Wellington.

Postmortems on those killed in Friday's shootings at Christchurch's Al Noor and Linwood mosques began early Sunday, Chief Coroner Deborah Marshall said.

A list of victims' names had been shared with families, but will not be released until they are formally identified, she said.

The prime minister's office was one of more than 30 recipients of the alleged murderer's so-called "manifesto" sent out nine minutes before the attacks.

Ardern said it was reported to parliamentary security within two minutes.

"It did not include a location. It did not include specific details," she said.

The prime minister also said the suspect will "certainly face the justice system of New Zealand for the terrorist attack he has committed here" and that gun reform laws would be raised in a Cabinet meeting on Monday.

She added that there were "further questions to be answered" about the role of social media platforms in bringing down content such as the video live streamed by the shooter.

"This is an issue that I will look to be discussing directly with Facebook," said Ardern referring to the social media site where the video was streamed.

The death toll of the attack rose to 50 on Sunday after the discovery of an additional body at Al Noor mosque, Police Commissioner Mike Bush said.

Another 50 were wounded in the attacks, with 34 still hospitalized, of which 12 were in critical condition, in addition to a 4-year-old girl who was taken to Auckland's Starship hospital and listed as critical, Christchurch hospital chief of surgery Greg Robertson said.

Australian Brenton Tarrant, 28, appeared in Christchurch District Court on Saturday charged with one count of murder.

He did not enter a plea and was remanded in custody to appear next on Apr. 5.

More charges were expected to be laid in the coming days.

Commissioner Bush said that of the two people apprehended at a cordon on Friday, one woman had been released without charges and a man was charged with firearms offenses.

"At this point, we do not believe they were involved in those attacks," Bush said.

He said another man had also been arrested as a result of the investigation.

An 18-year-old will appear in court on Monday but Bush said his arrest was "tangential" and he was not believed to have been involved in the attacks.

One other person who armed himself to assist children on Friday was later released.

It appeared the gunman may have been the sole perpetrator of the attacks, he said.

"At this point, only one person has been charged in relation to these attacks," Bush told reporters. "I will not be saying anything conclusive until we are absolutely convinced as to how many people were involved."

Meanwhile, Prime Minister Ardern laid a wreath and met with members of the Islamic community at a mosque in Wellington on Sunday as thousands of members of the public continued to hold vigils for the victims and express solidarity.

A day earlier, Ardern announced gun-law reforms and met with the wounded, families of the victims and members of the Muslim community in Christchurch where she expressed her support.

This weekend the press started revealing identities of those who were thought to have lost their lives, the youngest being 3-year-old Mucad Ibrahim.

He was in Al Noor mosque with his father and older brother Abdi when the attacker began firing.

His father and brother escaped but they have not been able to find Mucad.

Among the dead at Al Noor was Sayyad Milne, 14, whose father described him a "brave little soldier," Naeem Rashid, 50 - who has been hailed a hero after trying to stop the shooter - and his son Talha, 21, as well as Haji-Daoud Nabi, 71, who died trying to shield another person, his son said.

The victims also included people from different nationalities, including the South Asian countries of Pakistan, India and Bangladesh.

The Indian authorities on Sunday confirmed the death of five people from the country in the tragedy, whereas Bangladesh confirmed three dead and Pakistan six.

The government of Pakistan has decided to honor Naeem Rashid, who succumbed to his injuries received while trying to stop the attacker in Christchurch.

Rashid, a 52-year old teacher, had moved from Pakistan's Abbottabad to New Zealand in 2009 to pursue his doctorate. His son too died in the attack.

The cricket team of Bangladesh, which was on a tour of New Zealand, had a narrow escape as they were within the vicinity of the Masjid al Noor mosque, where they had intended to offer their Friday prayers.

The 19 members of the team returned to Bangladesh late Saturday after the bilateral cricket series was canceled in the aftermath of the events.