Dozens killed in Christchurch mosque attack

So far, police have arrested four people in connection with the attack on two Christchurch mosques -- three men and one woman.

In a social media post just before the attack, an account that is believed to belong to one of the attackers posted a link to an 87-page manifesto that was filled with anti-immigrant, anti-Muslim ideas and explanations for an attack. The manifesto was not signed.

TVNZ journalist Anna Burns-Francis told CNN at least one of the shooters is believed to be an Australian national, while a witness from the scene described a man "white, aged in his 30s or 40s and wearing a uniform."

CNN has not been able to independently confirm any information about any of the attackers at this stage.

A spokeswoman for Facebook New Zealand, Mia Garlick, said videos which appeared to show the Christchurch shootings have been taken down.

"New Zealand Police alerted us to a video on Facebook shortly after the livestream commenced and we quickly removed both the shooter’s Facebook and Instagram accounts and the video," the spokeswoman said.

The disturbing video which has not been verified by CNN, appears to show a gunman walking into the mosque and opening fire.

New Zealand police have asked social media users to not share the video which has already been distributed widely online.

The strict lockdown on Christchurch's school has been lifted, New Zealand police announced on their social media.

"We would like to reassure members of the public that there is a large police presence in the city and the safety of the community is our priority," the statement said.

It follows the announcement that four people have been arrested over the attack on two mosques -- three men and one woman.

There is no news yet on whether the lockdown on government buildings has been lifted.

The shootings occurred on Friday -- the busiest day for many mosques around the world when Muslims convene for the Friday prayer.

Many Muslims take time off of work to join their congregation and the Friday prayer normally takes place at around midday. Police said they received reports of shots fired at 1.40 p.m. local time.

Muslims across New Zealand have been advised by the authorities to avoid attending mosques today.

TVNZ journalist Anna Burns-Francis told CNN at least one of the shooters is believed to be an Australian national.

The journalist said that emergency services from across New Zealand have been sent to Christchurch to assist in the growing emergency situation.

She said TVNZ has confirmed nine deaths already although there could be many more in the two attacks. Police have not given any official numbers as yet but said it is "significant."

"This is a deeply unsettling, disturbing attack, we've never witnessed anything like this before in New Zealand," she said.

CNN has been unable to verify the nationality of the gunmen or a possible death toll.

This morning's mass shootings took place in central Christchurch, close to where school children taking part in the Global Climate Strike were protesting.

The city council has advised parents to contact their staff who will take their details and check if their child is now in a civic building. They told concerned parents not to "try to come and collect your children until police say it is safe for people to come into the central city."

Environmentalist Bill McKibben, founder of the 350.org site, noted the awful contrast between the two events on Twitter. He wrote:

Local resident Robert Weatherhead told CNN affiliate, NEWSTALK, that he took in people who escaped from the Masjid al Noor mosque on Deans Avenue.

He described the gunman as "white, aged in his 30s or 40s and wearing a uniform," but he had not been able to ascertain what the uniform was.

Benjamin Jellie said he ran outside when he heard gunshots. Oakward Close is the Christchurch neighborhood where the Masjid al Noor mosque is located.

Mark Nichols, manager of Premium Tyres and Auto in Linwood, the location of the second mosque shooing, said a gunman ran past his shop.

New Zealand police commissioner Mike Bush said again there have been "multiple fatalities" but couldn't say at this point how many. "It is significant," Bush said.

Bush added the identities of all the victims weren't known at this stage.

The New Zealand police press conference has now wrapped up. Bush said there would be more information available soon.

New Zealand police commissioner Mike Bush told reporters that there were multiple improved explosive devices attached to vehicles as part of the attack.

Bush said these had been "made safe by the defense force."

"This goes to the seriousness of the situation," he said.

He said that police were not assuming the situation was limited to Christchurch at this stage.