Pope Francis called the mass shooting in Christchurch a "horrible attack" and implored people around the world to fight anti-immigrant and white supremacist extremism espoused by the alleged killer.
"I pray for the dead, the injured and their families," the pope said. "I am close to our Muslim brothers and to all that community, and I renew an invitation to join in prayer and gestures of peace to combat hate and violence. Let's pray together in silence for our Muslim brothers who have been killed."
The alleged gunman, Brenton Harrison Tarrant, launched his vicious attack Friday afternoon in Christchurch on the Al Noor and Linwood mosques, where Muslims were gathered for prayer services.
In a twisted move, Tarrant allegedly livestreamed the attacks on Facebook live, showing his face on camera and his arsenal of high-powered weapons and ammo clips used in the massacre lying on the passenger side floor of his vehicle. The livestream was broadcast for 17 minutes before Facebook officials took action to end it.
Tarrant, a 28-year-old Australian, allegedly started the attack at the Al Noor mosque, killing 42 people and wounding scores of others before driving three miles to the Linwood mosque and fatally shooting eight victims, New Zealand police said. Tarrant was captured by police when they rammed his car off the road as he tried to flee.
The slain victims ranged from age 3 to 77, and included at least four women, officials said.
The alleged gunman's grandmother and uncle spoke out against the attack, saying they are as stunned as anyone, saying their relative is "obviously not of sound mind."
"It's just so much for everything to take in that somebody in our family would do anything like this," the grandmother, Marie Fitzgerald, told 9News in Australia in an exclusive interview.
She said her grandson spent most of his time on computers, "learning all the ins and out" and playing video games.
"It's only since he traveled overseas, I think that that boy has changed completely [from] the boy we knew," the grandmother said.
Tarrant's uncle, Terry Fitzgerald, said he couldn't believe his nephew was involved in what New Zealand officials described as the "worst terrorist attack in New Zealand's history" until he saw his photo on TV news reports.
"We say sorry, for the families over there, for the dead and the injured. Yeah we just, can't think nothing else, just want to go home and hide," Terry Fitzgerald told 9News.
New Zealand Prime Minister Jacinda Ardern said that some of the bodies would be returned to their loved ones on Sunday for burial. Graves were already being dug for the victims even as authorities were still working to identify the victims.
Mike Bush, New Zealand's commissioner of police, said authorities are keenly "aware of the cultural and religious needs" of victims, whose faith customarily calls for Muslims to be buried within 24 hours of death.
Authorities are working as "quickly and sensitively as possible" to return the bodies to grieving family members, Bush said Saturday.
Investigators said three other people arrested in the aftermath of the attacks apparently were not involved in the massacre and released.
Bush said an additional 50 people were wounded in the rampage. He said 36 remained hospitalized, two in critical condition.
Tarrant has been charged with murder. In his first court appearance on Saturday, Tarrant briefly flashed hand gestures that some witnesses and officials described as white supremacist signals.
In online writings, Tarrant, according to investigators, spewed hatred aimed at non-white people immigrating to Western countries.
Tarrant also cited in his online writings the 2015 attack by white supremacist Dylann Roof that left nine African-American worshippers dead at the Emanuel African Methodist Episcopal Church in Charleston, South Carolina, according to investigators. He also said in his writings that he was inspired by Anders Breivik, a Norwegian far-right terrorist, who killed 77 people in a rampage in Norway, officials said.
On Friday, Trump was asked by ABC News' Terry Moran if he considered white nationalism on the rise across the world.
"I don't, really," Trump, sitting at his desk in the Oval Office, replied. "I think it's a small group of people that have very, very serious problems."
FBI statistics show that the number of hate crimes in the United States rose 17 percent from 2016 to 2017. Of the 6,000 suspects who allegedly carried out the crimes on 8,000 victims, 58 percent were motivated by hate and 22 percent by religion, according to the FBI.
Lianne Dalziel, the mayor of Christchurch, told ABC News that the mass shooting exposed the rise of extremism in her country, which recorded just 35 murders in all of 2017. Dalziel pointed out that the hatred she has seen locally was imported to inflict damage on a safe city in a safe country.
Dalziel said cities across the world need to gather together and unify around diversity.
Tom Bossert, the former homeland security adviser to Trump and former deputy homeland security adviser under President George W. Bush, said on ABC's "This Week" on Sunday that Trump isn't downplaying the hate crimes in the country, but apparently comparing the numbers to atrocities committed to well-organized groups like ISIS.
"Both are morally repugnant and difficult challenges, and so we don't want to downplay it," Bossert told ABC News' chief anchor George Stephanopoulos. "I think what the president said is it's a smaller threat. I hope he doesn't maintain the position that it's not a threat at all. Some resources are needed. Clearly this is a trend that needs to be addressed."
Bossert also said authorities should consider requiring delays on live broadcasts or live streaming to prevent others bent on committing mass killings from following in the alleged footstep of the Christchurch mass shooter.
"There's no negative or downside to forcing some delay into that broadcast," Bossert said. "It will require some time and money, but I think it's something we should consider."
Jae Johnson, former secretary of homeland security under President Barack Obama, said on "This Week" that companies that provide social media platforms be required to be more vigilant when it comes to policing hate speech.
"In social media now there are very very few barriers to entry and, frankly, standards of exit," Johnson said.
Johnson also suggested that voters should require a prerequisite for all candidates running for public office to adopt a more civil tone in what they say publicly and to lower the level of espousing ideas that can be interpreted as condoning acts of extremist hate.
"Americans do listen to their leaders," Johnson said.