Allegations of Islamophobic hate crimes soared in the week following the massacre of Muslim worshippers at two mosques in Christchurch by a far-right extremist, a charity has said.

Tell Mama, a group that monitors anti-Muslim incidents, said on Friday that it received a six-fold increase in reports compared to the previous week.

The charity said it had been told of 95 incidents following the New Zealand attack, all but 10 of which contained references to that atrocity. A week before there were 13 reports.

On Friday last week 50 people were murdered by a gunman at two mosques in the city during Friday prayers.

Mosques in the UK have been on high alert, with increased police patrols, since the terror attack and hate crimes have been reported across the nation.

Five mosques in Birmingham had windows smashed, prompting an investigation by counter-terrorism officers. On Friday a 34-year-old man was arrested on suspicion of racially aggravated criminal damage.

Also a 50-year-old man was charged with offences including attempted murder and racially aggravated fear of violence following a terror attack in Stanwell, Surrey.

Commenting on the data, Tell Mama director Iman Atta told the Guardian: "This shows that some people see Muslims as fair game for hate and it is now clear that we have an ongoing and persistent ideology of hate that is generating a focus on Muslims.

"Muslims in New Zealand were killed and British Muslims feel the anger of bigots. It is perverse."

The National Police Chiefs' Council hate crime lead said attacks such as the one in Christchurch often prompt a rise in reporting, due to an increase in hostility and fear.

Assistant Chief Constable Mark Hamilton said: "Experience tells us that we should sadly expect that a horrific attack such as the one in Christchurch will have an impact on levels of hostility in the UK but it will also increase the fear of crime in affected communities.

"Both of these factors are likely to increase reporting levels."

The Muslim Council of Britain said the statistics were "deeply worrying" and called for a zero tolerance approach from politicians, while praising New Zealand Prime Minister Jacinda Ardern's "bold leadership".

"It seems an environment has been created in our society over a period of time, fed in part by sections of the media and political commentators, that Muslims are fair game," a statement said.