CHRISTCHURCH, New Zealand — At least 49 people were killed in mass shootings at two mosques full of worshippers attending Friday prayers in an attack broadcast in horrifying, live video by an immigrant-hating white nationalist wielding at least two assault rifles and a shotgun.

  • 3 men, 1 women detained; one of the men charged with murder
  • One of the people detained has been released
  • One attacker described as white Australian who is anti-Muslim
  • Authorities say bombs were placed under vehicles; bombs defused
  • Witnesses describe the shootings

New Zealand's Prime Minister Jacinda Ardern is calling the attacks in Christchurch an "an extraordinary and unprecedented act of violence" and said many of those impacted may be migrants and refugees.

"It is clear that this can now only be described as a terrorist attack," Ardern said.

The attack occurred at the Masjid Al Noor mosque in central Christchurch at about 1:45 p.m. local time.

Witness Len Peneha said he saw a man dressed in black enter the mosque and then heard dozens of shots, followed by people running from the mosque in terror.

Peneha, who lives next door to the mosque, said the gunman ran out of the mosque, dropped what appeared to be a semi-automatic weapon in his driveway, and fled.

Peneha said he then went into the mosque to try and help.

"I saw dead people everywhere. There were three in the hallway, at the door leading into the mosque, and people inside the mosque," he said. "It's unbelievable nutty. I don't understand how anyone could do this to these people, to anyone. It's ridiculous."

There was a second shooting at the Linwood Masjid Mosque that Ardern said killed 10 people. Mark Nichols told the New Zealand Herald he heard about five gunshots and that a Friday prayer-goer returned fire with a rifle or shotgun.

Nichols said he saw two injured people being carried out on stretchers past his automotive shop and that both people appeared to be alive.

The gunman behind at least one of the mosque shootings left a 74-page manifesto that he posted on social media under the name Brenton Tarrant, identifying himself as a 28-year-old Australian and white nationalist who was out to avenge attacks in Europe perpetrated by Muslims.

Tarrant allegedly said he chose New Zealand to show that even remote parts of the world have what he calls "mass immigration" problems and radical Islamic terror attacks in Europe.

He also hoped to create a political rift between American liberals and conservatives over how he used firearms.

While saying he could have used any means to kill those in the attack, such as fire, planes, driving a van and other methods not involving guns, he allegedly wrote that he chose firearms because of the affect they would have on society, particularlly in America. 

"With enough pressure the left wing within the United states will seek to abolish the second amendment, and the right wing within the US will see this as an attack on their very freedom and liberty. This attempted abolishment of rights by the left will result in a dramatic polarization of the people in the United States and eventually a fracturing of the US along cultural and racial lines," he allegedly wrote.

Australian Prime Minister Scott Morrison confirmed that the man who wrote the manifesto was an Australian-born citizen. 

Morrison also took to Twitter to condemn the attack.

Police said the investigation has extended 360 kilometers (240 miles) to the south, where homes in Dunedin were evacuated around a "location of interest." A police statement gave no further detail of how it might be linked to the attacks.

Authorities have not specified who they detained, but said none had been on any watch list.

Authorities took three men and a woman into custody. One of the men has been charged with murder, according to Police Commissioner Mike Bush. 

One person was later released and police stated that one of the "arrests" — no charges have been given for those arrests — did not relate to the shooting.

He said authorities were not aware of other suspects beyond the four who were detained but they could not be certain.

Witnesses say the attackers went into the places of worship and began shooting at random.

Bush said the defense force had defused a number of improvised explosive devices that were attached to vehicles stopped after the attacks.

While there was no reason to believe there were any more suspects, Ardern said the national security threat level was being raised from low to high, the second-highest level.

National carrier Air New Zealand canceled at least 17 flights in and out of Christchurch, saying it could not properly screen customers and their baggage following the shootings.

Los Angeles, Minneapolis, and New York law enforcement say they are adding extra police patrols around mosques as a precaution.

President Donald Trump condemned the attack.