The victims were targeted as they gathered at the mosques for Friday prayers, leaving the country's Muslim community -- and the world -- in mourning.
As authorities begin to release information on the victims, here's what we know:
Daoud Nabi sought asylum in New Zealand more than 40 years ago after fleeing Afghanistan with his two sons.
Christchurch, the place he's called home since 1977, offered hope and safety for him and his family.
Authorities have not released details and information on the victims, but his son, Yama Nabi, confirmed his death.
Naeem Rashid, 50, and his son Talha Rashid, 21, were among nine Pakistanis who were killed in the mosques, according to Mohammad Faisal, spokesman for Pakistan's Ministry of Foreign Affairs.
Rashid has been praised for rushing the attacker during the attack, possibly preventing more deaths.
Pakistan's Prime Minister Imran Khan announced via Twitter on Sunday that Naeem will receive a posthumous award for his bravery.
"We stand ready to extend all our support to the families of Pakistani victims of the terrorist attack in Christchurch. Pakistan is proud of Mian Naeem Rashid who was martyred trying to tackle the White Supremacist terrorist & his courage will be recognized with a national award."
Speaking to CNN in Abbottabad, Pakistan, Dr. Khurshid Alam said his brother, the elder Rashid, was an academic who been living in New Zealand for seven years.
"He used to teach at a university," Alam said. "My nephew (Talha) was a student."
Pakistani nationals Sohail Shahid, Syed Jahandad Ali, Syed Areeb Ahmed and Mahboob Haroon died in the attack, Pakistan's Ministry of Foreign Affairs confirmed Saturday.
Shah Mahmood Qureshi, the foreign minister of Pakistan, posted a statement on Twitter, along with pictures of those six victims.
"My heart is filled with sorrow as I confirm the deaths of the following Pakistanis who embraced Shahadat in the horrific terrorist attack in Christchurch, New Zealand," Qureshi's tweet read. "To their families, I express my deepest sympathies and promise to facilitate them to the best of our abilities."
On Sunday, Pakistan's Ministry of Foreign Affairs added Zeeshan Raza along with his father, Ghulam Hussain and his mother, Karam Bibi to the list of Pakistanis killed in the massacre.
The three had previously been listed as missing.
"I received a phone call and my whole world just came crashing down. I've lost a part of me," said his friend and fellow goalkeeper, Hamish Mitchell. "We've formed not just a friendship, a brotherhood, it's just unbelievable."
Another friend, Hady Osman, told CNN it was Atta's "dream to represent New Zealand in a futsal world cup," adding that not only was Elayyan a talented sportsman but incredibly passionate about his work as a UI/UX designer. On holiday last year, Osman said Elayyan taught him how to ski, saying that his friend's positive attitude and encouraging ways embodied his character.
"He gives everyone around him belief and confidence that anything is possible," Osman said.
Added his friend Ronan Naicker: "He was just a true gentleman, a true leader, someone who was there for everyone. He was really intelligent guy, he had his own company working in apps to the point that some of the younger boys would go to him for advice and he'd talk to them about life, work," said Naicker.
Elayyan leaves behind a young daughter and a wife.
Khaled Mustafa, a refugee from Syria, was killed in the attack, Syrian Solidarity New Zealand said on its Facebook page. He was at the mosque with his two sons for Friday prayers when the shooter opened fire.
The group's spokesman, Ali Akil, told New Zealand news media company Stuff that he had spoken to Mustafa's wife, who was "devastated and deeply horrified." He added she did not want to speak with the media during this time, Stuff reported.
Hamza Mustafa, 14, was attending Friday prayers with father, Khaled, and his younger brother, Zaid, according to Syrian Solidarity New Zealand.
Mustafa's mother confirmed that her eldest son, Hamza, had died and that her younger son, Zaid, 13, was injured, Akil said. Zaid is in stable condition in Christchurch Hospital, he said.
Zaid does not know that both his father and brother have been killed, nor does the younger sister, Akil said.
Lilik Abdul Hamid, from Indonesia, was killed in the shooting, Indonesia's Foreign Ministry said Saturday on Twitter.
The ministry tweeted its "deep condolences" and offered "prayers for the deceased and the family left behind."
Five Indian nationals died in the attack, the Indian High Commission in New Zealand said in a Tweet on Sunday.
"With a very heavy heart we share the news of loss of precious lives of our 5 nationals in ghastly terror attack in #Christchurch," it said, before listing five names: Maheboob Khokhar, Ramiz Vora, Asif Vora, Ansi Alibava and Ozair Kadir.
"We deeply mourn loss of all other innocent lives including people of Indian origin," the message said.
Four Egyptians were among the shooting victims, according to the Twitter page of the Egyptian Immigration Ministry, which called the attack "despicable."
Mounir Sulaiman, 68; Ahmed Jamal Aldean Abdulghani, 68; Ashraf al-Morsi and Ashraf al-Masri were killed in Friday's shooting, the ministry said.
Four Jordanians were killed, and five who were wounded are being treated in the hospital, Jordan's Foreign Ministry said in a statement Saturday.
New Zealand Prime Minister Jacinda Ardern said that Pakistan, Turkey, Saudi Arabia, Bangladesh, Indonesia and Malaysia were among the countries whose nationals were involved in the attack.
Christchurch hospital said they have 34 patients, 12 of them in intensive care. One girl was transferred to a children's hospital. Many of the victims will require multiple surgeries, they said.
This story will be updated as more information on the victims becomes available.
CNN's Sophia Saifi, Christina Maxouris, Jomana Karadsheh, Loumay Alesali, Madeline Holcombe and David Williams contributed to this report.