The leaders of New Zealand's spy agencies have weighed in on the risk of copycat attacks in the wake of the Christchurch terror mosque shootings.
It has almost been a month since 50 people were killed when a suspected white supremacist gunman from Australia opened fire on worshippers at two Christchurch mosques on March 15.
Prime Minister Jacinda Ardern described the event as New Zealand's "darkest day", and it has sparked concerns about the potential for others to copy the alleged shooter, particularly with Anzac Day looming on April 25.
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Speaking for the first time since the attack, the leaders of the Government Communications Security Bureau (GCSB) and New Zealand Security Intelligence Service (SIS), Andrew Hampton and Rebecca Kitteridge, have expressed concern about copycats and retaliation.
"At the moment, we still have a high threat level, and the information that underlies that helps all of those agencies to make sure that they can mitigate the risks that we see at the moment," Kitteridge said.
In the aftermath of the Christchurch attack she said there's been a "huge public outpouring to us of leads - and to police - of concerns about various people in the community".
"I'm delighted to tell you that most of those are not anything of security concern - but we are working through them methodically. At the moment we all still need to be quite vigilant."
Hampton said as well as the risk of copycats, there is also the risk of retaliation - and not just here in New Zealand. He said it "relates to New Zealand interests offshore as well, which is an important focus for us".
A man was arrested on Thursday outside the Al Noor mosque where one of the shootings took place, after he allegedly yelled abuse outside as he donned a T-shirt that read 'Trump for New Zealand'.
Last month, jihadist groups around the world - including the Islamic State - threatened retaliation for the Christchurch shootings, and called on Muslims to take revenge. The Prime Minister was also threatened on social media.
Police in the Australian state of Victoria also said they were investigating a report of "concerning" social media posts that detailed plans to carry out a mass shooting at the Islamic Society of Geelong mosque.
And four people were arrested in the UK in three separate incidents after referencing the Christchurch attack as part of racial abuse.
Five Returned Services Associations (RSAs) in New Zealand have cancelled Anzac Day services, fearing violence. Police said some services would be consolidated due to the current high terror alert.
Supt Karyn Malthus said while there was no specific threat to any services, police would continue to provide a visible presence nationwide.
The leaders of the GCSB and SIS said they are taking every threat seriously, and are continuing to assist police.
A royal commission of inquiry was announced last month to investigate whether the spy agencies could have prevented the tragedy, including whether they were too focused on Islamic extremists and not white supremacy.