Prime Minister Jacinda Ardern says it's devastating to hear of an increase in Islamophobic threats in the UK since the Christchurch attack.

The Prime Minister said there have been reports of a large increase in threats and hate crimes following the shooting.

"I think it's devastating to know that when a community has been the subject of a direct attack like this, they would then be subject to threats. I think that's utterly despicable," she said.

The Guardian is reporting a 593 per cent rise in reported crimes in the week since the terror attack that left 50 people dead and nearly as many injured.

The number of incidents recorded is higher than it was after the terrorist attack at an Ariana Grande concert in 2017, charity Tell Mama told the newspaper.

Many of the incidents included direct references to the Christchurch attack.

Ardern said she hasn't been advised of the same thing happening here, but is urging people who have been threatened to report it to police.

"If you've seen any information that you think our intelligence services should know, they are taking them seriously, they are following them up."

New Zealanders are already facing charges for social media comments made in the days since the attacks. One Christchurch teenager has been charged with inciting extreme violence, while a businessman has been charged with sharing footage of the shooting.