New Zealand police have arrested three people in connection with the attacks including one man who has been charged with murder.
Australian Prime Minister Scott Morrison on Friday confirmed the attacker at the Masjid al Noor mosque was an Australian. The police had secured IEDs (improvised explosive devices) strapped to vehicles.
New Zealand's Prime Minister Jacinda Ardern calls it "one of New Zealand's darkest days".
"Police are now in attendance at a property of Somerville Street, Dunedin", the New Zealand force said on Twitter.
Police said they have mobilized every national police resource to respond to the incident. "I couldn't put it into words how I'm feeling right now", Williams said.
A spokesman for New Zealand's interior ministry said the video is likely to be classified as objectionable content under local law, and could be illegal to share.
New Zealand's deadliest mass shooting occurred in 1990 when a loner killed 13, including women and children, within 24 hours in Aramoana, a small village. "It must have been an automatic - no one could pull a trigger that quick", the man, who did not wish to be named, told AFP.
The identities of the victims - further nationalities could be among the casualties, with Afghan and Malaysian government confirming nationals injured in the attack.
"The content of the video is disturbing and will be harmful for people to see", he said.More news: Bale: Manchester United boss Solskjaer fails to rule out move
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And West Suffolk MP Matt Hancock, who is also health secretary, Tweeted: "Desperately shocked at the bad terrorist attack on New Zealand mosques".
- The 28-year-old Australian described his anti-immigrant motives in a manifesto.
The gunman said he was not a member of any organization, acted alone and chose New Zealand to show that even the most remote parts of the world are not free of "mass immigration".
Bangladeshi Minister of State for Foreign Affairs Shahriar Alam said it was "extremely lucky" the country's cricket team, in Christchurch for a match against New Zealand, did not suffer casualties.
New Zealand authorities confirmed "multiple" deaths but they did not say how many or identify any victims.
The Muslim worshippers had congregated for Friday prayers, Islam's holy day of the week.
Turkish President Recep Tayyip Erdogan addressed a message "to the Islamic world and the people of New Zealand, who have been targeted by this deplorable act", which he described as "the latest example of rising racism and Islamophobia".
Police are reported to be patrolling United Kingdom mosques following the terror attack in Christchurch, New Zealand, in which a gunman targeted Muslims.
"From what we know, it does appear to have been well planned", she said, adding that in addition to the dead another 20 people were seriously injured.
Armed police on Linwood Ave and specialist armed police after the Linwood Mosque came under attack.