The Government Communications Security Bureau also said in a statement on Monday night that it welcomed an inquiry that Prime Minister Jacinda Ardern has ordered into intelligence and security services that failed to detect the risk from the attacker or his plans.
There have been concerns intelligence agencies were overly focused on the Muslim community in detecting and preventing security risks. On Friday, a white supremacist went on a shooting rampage in two mosques in Christchurch, killing 50 people.
Australia's prime minister has urged world leaders to crack down on social media companies that broadcast terrorist attacks in the aftermath of the New Zealand mosque shootings.
Prime Minister Scott Morrison has written to G-20 chairman Japanese Prime Minister Shinzo Abe calling for agreement on "clear consequences" for companies whose platforms are used to facilitate and normalize horrific acts.
Australian Brenton Tarrant has been charged with murder over the attack on two mosques in Christchurch that killed 50 people and left another 50 injured.
The attacks were live-streamed on Facebook.
Morrison says: "Social media companies are international businesses and it's up to the international community to force them to act."
6 a.m. Tuesday
Authorities say alleged Christchurch mosque gunman Brenton Tarrant arrived in Hungary as a tourist last November on a train that runs between Timisoara, Romania, and Budapest, Hungary.
Hungary's Counter-Terrorism Center said in a statement that Brenton Tarrant entered the country Nov. 26, 2018 at the border railway crossing in Lokoshaza, about 250 kilometers (155 miles), southeast of Budapest.
Tarrant is accused of shooting worshippers at two mosques in New Zealand last week. Fifty people have died and dozens are still hospitalized.
The statement says said Tarrant was traveling by himself when he entered Hungary, did not appear on any terrorist databases, had not been flagged by authorities elsewhere and would have been allowed to stay in Hungary for up to 90 days without a visa.
The center says it is still investigating what Tarrant did and where he went while he was in Hungary.
President Donald Trump says he is being unfairly blamed for the New Zealand mosque attacks in which 50 people died.
Trump tweeted that the media "is working overtime to blame me for the horrible attack in New Zealand." He adds: "They will have to work very hard to prove that one."
The gunman in last week's attacks left a document in which he called himself a white nationalist and referred to Trump as "a symbol of renewed white identity."
Trump had expressed sympathy for the victims, but played down the threat of white nationalism across the world, saying he didn't consider it a rising threat despite data suggesting it's growing.
In the past, Trump has drawn criticism for saying "both sides" were to blame for violence at a deadly white supremacist demonstration.
Turkey's president has shown parts of a video taken by the attacker who killed 50 people at two mosques in New Zealand to comment on what he called rising Islamophobia.
President Recep Tayyip Erdogan showed the clips during campaign rallies for March 31 local elections. The video, which was blurred but had clear sounds of automatic gunfire, was shown to thousands of people at the rallies and was aired live on Turkish television.
Erdogan used the video to comment on attacks on Islam and rising Islamophobia. He referred to a manifesto by the suspected attacker, Brenton Tarrant, in which he threatened Turks and vowed to make Istanbul "Christian owned once more."
New Zealand Foreign Minister Winston Peters said Monday he told his Turkish counterpart the video doesn't represent New Zealand.
The top cleric in the Muslim World League is traveling to New Zealand to pray for the victims of an attack on two mosques that killed 50 people.
The Saudi-based league said Monday that Secretary General Sheikh Mohammad Alissa will offer condolences to families of the victims, pray for the dead and visit the wounded.
An Australian white supremacist is charged with murder in the shootings.
After Friday's attack in Christchurch, Alissa issued a statement saying the barbarity and hatred displayed in the shootings "parallel" the violent acts of al-Qaida and the Islamic State group.
He said governments and faith organizations need to work together to encourage religious tolerance and understanding.
Pakistanis are observing a day of mourning to remember victims of the New Zealand mosque attacks and honor a man who died after trying to tackle the gunman.
Nine Pakistanis were among the 50 people killed when an immigrant-hating white nationalist opened fire at two mosques in Christchurch during Friday prayers. Among the slain worshippers was Naeem Rashid, a 50-year-old Pakistani who tried to snatch the gun from the attacker. Rashid moved to New Zealand from Pakistan with his family when he was 11.
On Monday, Pakistan's flag was flying at half-staff as a sign of respect for the victims.
Government officials, opposition leaders, relatives and friends visited the homes of Pakistanis killed in New Zealand to convey their condolences.
Relatives and family members of the slain Pakistanis said the victims were "martyrs."
9 p.m., Monday
Australian TV news networks have shown what they say are the mother and sister of alleged Christchurch mass killer Brenton Tarrant returning to their homes in eastern Australia with police searching for clues in the New Zealand mosque attacks.
Tarrant, an Australian, grew up in the New South Wales town of Grafton. But Prime Minister Scott Morrison said he has only spent 45 days in Australia in the past three years.
The two people identified as mother Sharon Tarrant and sister Lauren Tarrant did not comment to the media after police searched their homes. They are reportedly in protective police custody.
Nine News said they returned to their homes for the first time Monday since at least 50 people were slaughtered in Christchurch last Friday.
The mother lives in the New South Wales town of Lawrence and the sister in Sandy Beach.
Australian police said the aim of the search was to obtain material that could help New Zealand police in their investigation of the attack.
New Zealand Police Commissioner Mike Bush said the Australian police searches "haven't discovered any matters that would threaten their public."
New Zealand Police Commissioner Mike Bush says gunman who killed 50 people and wounded others at two Christchurch mosques acted alone but may have had support.
Australian white supremacist Brenton Tarrant was arrested moments after the shootings on Friday. He was charged with a single count of murder and a judge said Saturday he may face other charges.
Bush said at a Monday news conference that "We believe absolutely there was only one attacker responsible for this."
But he added that the support of other people hasn't been ruled out and is "a very, very important part of our investigation."
New Zealand prime minister Jacinda Ardern says gun law reforms will be announced within 10 days following the Christchurch shootings that killed 50 people.
She said Cabinet ministers had met and made an in-principle decision to tighten gun ownership but details still need to be worked out.
Ardern also announced an inquiry into the country's intelligence services.
The Australian white supremacist charged in the massacre wasn't detected before his well-planned attack on two mosques and there have been concerns intelligence agencies were overly focused on the Muslim community in detecting and preventing security risks.
Australia is making public grants available to help places of worship bolster security after an Australian white supremacist was accused of a terror attack in New Zealand.
Prime Minister Scott Morrison says 55 million Australian dollars ($39 million) in total will be made available to add security video, fencing, lighting and alarms.
Morrison says religious freedom has to start with the right to worship and meet safely without fear of violence.
Australian Brenton Tarrant was charged with murder over the shootings at two mosques in Christchurch in which 50 people were killed. He grew up in the New South Wales town of Grafton and had lived in New Zealand in recent years.