Dozens killed in Christchurch mosque attack

At least 49 people were killed and 20 seriously injured in two mass shootings at mosques in the New Zealand city of Christchurch.

Here's what we know so far:

A growing number of Democratic candidates running for US President in 2020 have tweeted prayers for the victims of the attack, and condemned acts of hate and violence.

Cory Booker

John Delaney

Kamala Harris

Amy Klobuchar

Bernie Sanders

Jay Inslee

Elizabeth Warren

Beto O'Rourke

Julian Castro

Kirsten Gillibrand

Pete Buttigieg

National security advisor John Bolton expanded upon the White House’s statement on the attack on New Zealand mosques, which he characterized as “what seems to be a terrorist attack” and a “hate crime.”

Bolton said the US is “very concerned” and is following the events “very closely.” 

He told reporters Friday morning:

Bolton continued, “We’re very concerned, we’re going to cooperate with New Zealand authorities to the extent we can if there’s any role we can play, but we’re obviously following the events there very closely.”

US President Donald Trump has tweeted in response to the attack.

His message follows an earlier White House statement in response to the mass shootings at New Zealand mosques that left 49 dead.

Global leaders have also been sending messages of support. "On behalf of the UK, my deepest condolences to the people of New Zealand after the horrifying terrorist attack in Christchurch," British Prime Minister Theresa May wrote on Twitter. "My thoughts are with all of those affected by this sickening act of violence."

"All our thoughts for the victims of heinous crimes against the mosques of Christchurch in New Zealand and for their loved ones," French President Emmanuel Macron added.

Flowers and messages have been left outside London's Finsbury Park Mosque, which suffered its own tragedy in 2017 when a man deliberately drove a van into pedestrians outside, killing one Muslim worshiper and injuring several others.

Speaking on CNN Talk, political commentator Ayesha Hazarika said that, as a Muslim, she is "sickened and frightened" by the attacks.

"We have a culture, a media and social media culture, that not only tolerates hatred to Muslims but celebrates it," she said. "Shame on the people who have promoted this kind of hate.

"I have friends who have contacted me saying they’re scared to go to mosques. Today is a dark day," said Hazarika.

Tech companies including Facebook, Twitter and YouTube are responding to the attacks, one of which appeared to be live-streamed by one of the shooters.

The disturbing video, which has not been verified by CNN, purportedly shows a gunman walking into a mosque and opening fire.

Twitter has a "dedicated team in place for managing exigent and emergency situations such as this," the company said in a statement to CNN.

Facebook is "removing any praise or support for the crime and the shooter or shooters as soon as we're aware," a spokesperson said.

But some experts have criticized the platforms for their response to other harmful content.

"While Google, YouTube, Facebook and Twitter all say that they're cooperating and acting in the best interest of citizens to remove this content, they're actually not because they're allowing these videos to reappear all the time," Lucinda Creighton, a senior adviser at international policy organization the Counter Extremism Project, told CNN Business.

Read more about the companies' responses here.

France is joining countries including the UK and the US in confirming that mosques and places of worship will see increased security on Friday.

Interior Minister Christophe Castaner ‏said he had asked local officials to "strengthen surveillance" at places of worship as a precaution. "Patrols will be provided in the vicinity of denominational spaces," he wrote on Twitter.

Officials in London and police in Los Angeles, New York and Minneapolis earlier announced that they would be stepping up security at mosques.

Queen Elizabeth II, who is New Zealand's monarch and the head of the Commonwealth, has released a message to the people of the country.

She said she was "deeply saddened" by the news, and paid tribute to emergency services.

Here's the full message: