40 killed in coordinated terrorist shootings at 2 mosques in New Zealand; 4 suspects in custody originally appeared on abcnews.go.com

Forty people were killed in a shooting attack on the southern island of New Zealand on Friday when a gunman opened fire inside two mosques.

The shootings in Christchurch, categorized as a terrorist attack, included 30 deaths at one mosque, New Zealand Prime Minister Jacinda Ardern said. Christchurch Hospital also confirmed it was treating 48 people for gunshot wounds, ranging from minor to critical.

The gunman, who was dressed in tactical gear, appeared to livestream video of the shooting on social media, according to New Zealand police, documenting his trip from his vehicle and into the worship center in central Christchurch, where he opened fire indiscriminately.

"This is one of New Zealand’s darkest days," Arden said in a press conference Friday afternoon.

Four people, three men and one woman, were taken into custody in the hours following the attack, but police have not released their identities. Australian Prime Minister Scott Morrison confirmed one of them was an Australian citizen.

Ardern said the four people were not on any active terrorist watch lists and it was "not a matter of someone slipping under the radar."

New Zealand Police Commissioner Mike Bush said there were "significant" fatalities reported, but he declined to offer a specific figure.

The shooter also opened fire in the surrounding area outside of the mosques. Police said they recovered two improvised explosive devices attached to vehicles in the area, but they were rendered safe.

"A serious and evolving situation is occurring in Christchurch with an active shooter. Police are responding with its full capability to manage the situation, but the risk environment remains extremely high," New Zealand Police tweeted. "Police recommend that residents across Christchurch remain off the streets and indoors until further notice."

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A spokesperson for the Canterbury District Health Board said it activated its mass casualty plan, putting public locations in the area on lockdown.

"Christchurch schools will be locked down until further notice," the police department tweeted. "Police thanks the public for their cooperation and will provide further updates to keep residents informed."

Those lockdowns were lifted several hours after the attack ended.

Witnesses said the attack occurred just before 1:40 p.m. local time as the worship leader gave the sermon.

"The Sheikh was giving the sermon on Friday prayers and it was 1:42 [p.m.] and the gun starts shooting and he just came in and he was shooting ad hoc," eyewitness Ramzan Ali told The Associated Press.

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Arden made reference to the nationalities of the victims, saying, "Many of those directly involved might be immigrants, refugees who chose to be here. They are us. The person who has done this, is not."

Morrison described the shootings as having been perpetrated by an "extremist, right-wing, violent terrorist, that has taken the lives -- stolen the lives -- in a vicious, murderous attack that has claimed so many New Zealanders."

Ali said he survived the shooting by hiding beneath a bench.

"Actually I haven't seen him because I just lie down under the bench thinking that if I get out, I'll get shot," he said. "I'm just keeping my fingers crossed so I could be alive."