Muslim leaders in the UK have called on the government to redouble its efforts to ensure the country’s mosques are protected in the wake of the shootings in Christchurch, New Zealand, as they said worshippers attending Friday prayers would be doing so in the face of “unabated Islamophobia”.

The warning came as British police stepped up patrols in Muslim areas and around places of worship in direct response to the terrorist attack, in which at least 49 people were killed and 48 injured.

About 100 counter-terrorism investigations are already under way to thwart extreme rightwing terror plots in Britain and those who might help them, the Guardian understands.

Britain’s top counter-terrorism officer, assistant commissioner Neil Basu, condemned the Christchurch attacks and said: “Today we will be stepping up reassurance patrols around mosques and increasing engagement with communities of all faith, giving advice on how people and places can protect themselves.”

Friday lunchtime is the main time of the week for Muslim prayers, when many mosques across the UK are busy.

Basu said UK experts were ready to support local authorities and that UK-based threats were also under constant review. He added: “Together with our intelligence partners we continually monitor the varied threats we face, including to and around places of worship and specific communities across the country, to ensure we have the most appropriate protective security measures in place to keep people safe.”

But amid persistent concerns about Islamophobia, Harun Khan, the secretary general of the Muslim Council of Britain (MCB), said Muslims were being forced to live in fear. “As the rest of us prepare to undertake our own Friday prayers today, we do so with the anxiety as to whether our mosques and communities are safe in the face of unabated Islamophobia and hostility against Muslims,” he said.

Khan also urged the Home Office to allow applications for its worship security fund to resume. Launched in 2016, the scheme helps churches, mosques, temples and gurdwaras to install alarms, security lighting and CCTV cameras. Bids for up to £56,000 per place of worship could be submitted between June and August last year.

The MCB also gave examples of the rise of Islamophobia and rightwing extremism in the UK, saying that in the last two months alone, two mosques in Newcastle and Manchester had been attacked by vandals who spray-painted Nazi swastika symbols.

On Friday, a mosque in Birmingham asked police for increased security after concerned worshippers contacted managers fearing similar attacks.

Kamran Hussain, the general manager of the Green Lane Mosque and Community Centre, spoke with counter terrorism officers asking them to provide an additional police presence during afternoon prayers following calls from the congregation.

Pensioner Mohammed Saleem, 82, was stabbed to death yards from his home, after attending prayers at the Green Lane mosque in 2013. The white supremacist terrorist, Pavlo Lapshyn, was jailed for life for the racially motivated murder.

Hussain said: “For those that may be worried about attending Friday prayers at the Masjid today, we have contacted the police for additional security. We are expecting additional presence from them. The general message to the community is to stay calm but vigilant.

“People have a lot of questions and we want to ensure they feel safe,” he added.

Meanwhile, Mohammed Kozbar, the general secretary of the Finsbury Park mosque in north London where Makram Ali was killed in an extremist attack in June 2017, criticised the Conservative party for its alleged role in fuelling Islamophobia in the UK.

Kozbar said: “They don’t recognise their problems within the party. It is not just the Conservative party but it is spreading in wider society as well.

“These far-right people are given the platform to spread this without being challenged. This is a disease and unless we deal with it in a strong way and tackle it in a proper way, this will result in similar incidents to what happened in New Zealand.”

The New Zealand attacker’s “manifesto” referenced the Finsbury Park attacker, Darren Osborne.

Worshippers in the West Midlands and Greater Manchester, both areas with a large Muslim population, were also being offered extra protection.

Assistant chief constable Matt Ward from West Midlands police said officers would be engaging with key religious buildings to reassure local people. “As we are all very aware we face a sustained and determined threat to our security,” he added.

He said that while there was no specific threat, “we appreciate that our local communities may have concerns”.

“I would like to reassure you that there is no increased threat to the people of the West Midlands.”

The far-right terror threat came to government and mainstream attention after the murder of the Labour MP Jo Cox in June 2016.

Last year, the Home Office released figures that showed the number of recorded hate crimes more than doubled in the past five years.

The monitoring group Tell Mama said there was a record number of anti-Muslim attacks and incidents of abuse reported in 2017, with women disproportionately targeted by mostly male, teenage perpetrators.

In its annual report, the group noted a surge in the number of Islamaphobic attacks, with 1,201 verified reports submitted in 2017, a rise of 26% on the year before and the highest number since it began recording incidents.

Iman Atta, the director of Tell Mama, said anti-Muslim sentiment was “becoming a global issue and a binding factor for extremist far-right groups and individuals”.

“It is a threat that needs to be taken seriously,” she added.

The security minister, Ben Wallace, sought to reassure British Muslim communities, saying: “Later today, the home secretary and I will be speaking to police counter-terrorism leaders and security services to discuss what further measures we can take to protect our mosques and our communities from any threat here in the United Kingdom.

“A terrorist is a terrorist and we shall deal with them exactly the same.”

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