New Zealand's Prime Minister Jacinda Ardern said on Friday that 40 people were killed and 20 seriously injured in attacks on worshippers at mosques in the city of Christchurch.
"It is clear that this can now only be described as a terrorist attack," she said. "From what we know, it does appear to have been well planned."
Police said two mosques were targeted and witnesses spoke of victims being shot at close range, with women and children also believed to be among those killed.
The gunman at one mosque was an Australian-born citizen, Australian Prime Minister Scott Morrison said in Sydney, describing him as "an extremist, right-wing, violent terrorist".
It was not immediately clear how many attackers were involved, but New Zealand police said that four people – three men and a woman – were taken into custody.
Commissioner Mike Bush said a number of IEDS (improvised explosive devices) were also found and neutralised by the military.
A Palestinian man who was in one of the mosques said he saw someone being shot in the head.
"I heard three quick shots, then after about 10 seconds it started again. It must have been an automatic – no one could pull a trigger that quick," the man, who did not wish to be named, said.
"Then people started running out. Some were covered in blood," he said, adding that he joined the fleeing crowd and managed to escape.
Video and documents circulating online – but not officially confirmed – suggested the gunman had streamed his attack on Facebook Live.
New Zealand police described it as "extremely distressing" and urged web users not to share it.
A manifesto had also been posted online on accounts linked to the same Facebook page, suggesting the attack was racially motivated.
A social media account had also posted a number of pictures of a semi-automatic weapon covered in the names of historical figures, many of whom were involved in the killing of Muslims.
Police, who initially imposed a city-wide lockdown, sent armed officers to a number of scenes.
"This is an evolving incident and we are working to confirm the facts, however we can confirm there have been a number of fatalities," Bush said.
"Police are responding with its full capability to manage the situation, but the risk environment remains extremely high."
An ashen-faced Ardern said she was unable to confirm the number of fatalities, with events still unfolding.
"It is clear that this is one of New Zealand's darkest days," she told reporters. "Clearly, what has happened here is an extraordinary and unprecedented act of violence."
The two known targets were the Masjid al Noor in central Christchurch, and a second mosque in suburban Linwood.
One witness told stuff.co.nz he was praying when he heard shooting -- and then saw his wife lying dead on the footpath outside when he fled.
Another man said he saw children being shot.
"There were bodies all over," he said. (AFP)
Last updated: 2019-03-15 HKT 14:38