By Charlotte Greenfield and Praveen Menon
CHRISTCHURCH/WELLINGTON, New Zealand (Reuters) - New Zealand Prime Minister Jacinda Ardern on Saturday promised to reform the country's gun laws, a day after at least one gunman attacked worshippers in two mosques, killing 49 and wounding 42 others.
The attack, labeled terrorism by the prime minister, was the worst ever peacetime mass killing in New Zealand and the country raised its security threat level to the highest.
Armed police were deployed at several locations in all cities, unusual in a country where levels of gun violence are low.
The gunman broadcast footage of the attack on one of the mosques in the city of Christchurch on social media. A "manifesto" was also posted online, denouncing immigrants as "invaders".
The video footage, posted live online as the attack unfolded, showed a man driving to the mosque, entering it and shooting randomly at people inside.
Worshippers, possibly dead or wounded, lay on the floor, the video showed. Reuters was unable to confirm the authenticity of the footage.
Police said three people were in custody including one man in his late 20s who had been charged with murder. He will appear in court on Saturday. Police have not identified the suspects.
"Our investigations are in their early stages and we will be looking closely to build a picture of any of the individuals involved and all of their activities prior to this horrific event," Police Commissioner Mike Bush said.
Ardern said the main perpetrator used five weapons during his rampage, including two semi-automatic weapons and two shotguns, which he was legally licensed to own.
"I can tell you one thing right now, our gun laws will change," Ardern told reporters.
The man facing murder charges was an Australian citizen who had spent a lot of time traveling overseas and spent time only sporadically in New Zealand, Ardern said.
None of those arrested had a criminal history or was on any watchlist in New Zealand or Australia.
Among the wounded, two were in a critical condition, including a four-year-old child, he said.
There was a heavy police presence at the hospital where families of the wounded had gathered. Funerals were planned on Saturday for some of the victims, several of whom were born overseas.
Dozens of people laid flowers at cordons near both mosques in the South Island city, which is still rebuilding after a devastating earthquake in 2011 that killed almost 200 people.
GRAPHIC: New Zealand shootings - https://tmsnrt.rs/2O3v80l
Leaders around the world expressed sorrow and disgust at the attacks, with some deploring the demonization of Muslims.
U.S. President Donald Trump, who condemned the attack as a "horrible massacre", was praised by the accused gunman in a manifesto posted online as "a symbol of renewed white identity and common purpose".
Asked by a reporter in Washington if he thought white nationalism is a rising threat around the world, Trump said: "I don’t really. I think it’s a small group of people that have very, very serious problems. I guess if you look at what happened in New Zealand perhaps that’s a case, I don’t know enough about it yet."
Ardern, who was flying to Christchurch on Saturday, said she had spoken to Trump, who had asked how he could help.
"My message was sympathy and love for all Muslim communities," she said.
Political and Islamic leaders across Asia and the Middle East voiced concern over the targeting of Muslims.
"I blame these increasing terror attacks on the current Islamophobia post-9/11," Pakistani Prime Minister Imran Khan posted on social media. "1.3 billion Muslims have collectively been blamed for any act of terror."
'SHOOTING EVERYONE IN THE MOSQUE'
One man who said he was at the Al Noor mosque told media the gunman burst into the mosque as worshippers were kneeling for prayers.
"He had a big gun...He came and started shooting everyone in the mosque, everywhere," said the man, Ahmad Al-Mahmoud. He said he and others escaped by breaking through a glass door.
Facebook said it had deleted the gunman's accounts "shortly after the livestream commenced" after being alerted by police. Facebook, Twitter and YouTube all said they had taken steps to remove copies of the videos.
Ardern said she had asked authorities to look into whether there was any activity on social media or elsewhere ahead of the attack that should have triggered a response.
Forty-one people were killed at the Al Noor mosque, seven at a mosque in the Linwood neighborhood and one died in hospital, police said.
The visiting Bangladesh cricket team was arriving for prayers at one of the mosques when the shooting started but all members were safe, a team coach told Reuters.
Muslims account for just over 1 percent of New Zealand's population, a 2013 census showed, most of whom were born overseas.
Social media was flooded with messages of shock, sympathy and solidarity.
One image shared widely was of a cartoon kiwi, the country's national bird, weeping. Another showed a pair of figures, one in a headscarf, embracing. "This is your home and you should have been safe here" the caption read.
(Additional reporting by Tom Westbrook, John Mair and Swati Pandey in Sydney; Writing by Lincoln Feast; Editing by Andrew Heavens and Sonya Hepinstall)