The Christchurch shooting has shocked New Zealand and the world, with politicians and global media reacting in disbelief.
Police confirmed on Friday afternoon that Christchurch had been placed into lockdown, with all schools closed until further noticed. Police later confirmed that four people had been taken into custody, including a woman.
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Witnesses have described a shooter opening fire at two mosques, one at Deans Ave and another near Linwood. There have also been reports of a third incident at Christchurch Hospital.
There are unconfirmed reports 27 people have been killed. Newshub has been told there were shots fired by a shooter dressed in military gear with a powerful rifle. One of the men arrested is Australian.
The Ministry of Health has advised people not to attend Christchurch Hospital unless it's an emergency, saying on Twitter: "All appointments have been cancelled this afternoon, and no staff or patients are to enter or leave the building."
News of the incident has spread across the world, with the Associated Press quoting a witness who said he saw a man dressed in black enter the Masjid Al Noor mosque and "saw dead people everywhere".
Prominent New Zealand figures have expressed their shock, with National leader Simon Bridges tweeting: "I'm shocked to hear about the incident unfolding in Christchurch. My heart goes out to the families and I stand with the Canterbury community."
It was confirmed Speaker of the House Trevor Mallard, ACT Party leader David Seymour and National MPs David Carter and Matt Doocey were locked in Canterbury University while the incident unfolded.
Staff told them there were "multiple coordinated simultaneous attacks".
Labour MP Ruth Dyson shared her sympathies on Twitter, saying her "thoughts are with our Muslim community here in Christchurch and with [New Zealand Police]"
Finance Minister Grant Robertson re-tweeted Dyson, saying: "Thinking of you all in [Christchurch]. Stay safe, stay together."
Auckland Mayor Phil Goff said his "thoughts are with the people of Christchurch and the Muslim community throughout New Zealand. Kia kaha."
Deputy Prime Minister Winston Peters also sent a tweet, saying: "This is an awfully, awfully, sad day for New Zealand. There are lessons here from which we must all learn."
The Governor General Dame Patsy Reddy said the shootings have shocked all New Zealanders.
"Our hearts go out to the people of Christchurch, especially the people directly affected by this afternoon's terrible violence. Our thoughts are with them, their families and friends," she said.
"Now, more than ever, is the time to affirm the values that we hold dear - compassion, kindness and tolerance."
An Al Jazeera report quoted a man who had blood on his clothes saying he hid under a bench at the Masjid Al Noor mosque as the gunman fired.
He said he said about 10 to 15 people were seen outside the mosque, "some alive, some dead".
The BBC quoted Prime Minister Jacinda Ardern's address to the nation, where she said the attack was one of New Zealand's "darkest days".
It also noted how the student march on climate change was being held the same day across the country, and that the Prime Minister had been in Taranaki talking to students.
After the shooting, police told those in Christchurch to go home, and schools were placed into lockdown.
The Huffington Post reported that Fridays are one of the busiest days of the week for Muslims, a day known for Friday 'Jummah' prayers, similar to Sunday Mass.
The article highlighted how the Prime Minister was "hesitant to label the incident a hate crime".