There are only two reasons why someone who is not invited to a fancy-dress party would put on a Scream-type mask.

One is to avoid being recognised, the other is to intimidate and terrorise.

The sinister figures who descended on Dennis Road on the outskirts of Birmingham city centre, wearing just such a disguise, achieved both aims.

Behind the masks — and hoodies — were militant Muslims. 'The Boys', as one sympathiser casually referred to them.

Dennis Road was not chosen at random. At the end of the cul de sac stands Anderton Park Primary.

Parkfield Community School in Birmingham where parents have been protesting against a 'No outsiders' programme that has been introduced by head teacher Andrew Moffatt

On the sign at the entrance gates is a rainbow motif with the word 'equality' written above it.

At Anderton, this means teaching children about families with, say, 'two mummies or two daddies', to foster tolerance and respect for everyone and prepare them for life in modern Britain.

But almost all of Anderton's 800 pupils are Muslims, and for Muslims, homosexuality is sinful.

The religious and cultural divide at the heart of this community has culminated in angry, but essentially peaceful, daily pickets outside the school, featuring placards reading 'My child, my choice', 'Our voice must be heard', and 'Let kids be kids'.

Not everyone would necessarily disagree with these views. Tory leadership candidate Esther McVey is one such voice. 'I'm very clear, the final say is with the parents,' she declared in a TV interview yesterday.

'And if parents want to take their young children — primary school children — out of certain forms of sex education, relationship education, then that is down to them.'

Few will feel comfortable, though, with the tone and tactics of the demonstrators turning the playground into an ideological battleground. Either way, some time after 9pm a few Sundays ago, a line was crossed. Things got nasty.

Muslim extremists received a tip-off that LGBT supporters were placing 'Love is the answer' posters and rainbow flags on the school gates.

At Anderton primary school, protestors wore Scream-type masks to intimidate and terrorise

The religious and cultural divide at the heart of this community has culminated in angry, but essentially peaceful, daily pickets outside the school, featuring placards reading 'My child, my choice', 'Our voice must be heard', and 'Let kids be kids'

Suddenly, the small party of supporters — mostly women and some children — were penned in by the masked thugs, who leapt out of cars and began pelting them with eggs.

Houses in the row of Victorian terraces with rainbow flags or stickers in the window were also targeted and told that next time 'homes with flags will get bricks'.

'It was really, really scary,' said one visibly shaken young man, a non-Muslim who lives on Dennis Road.

Police arrived after the culprits had fled. They are investigating three separate reports of assault and two of criminal damage.

The incident prompted the intervention of West Midlands Chief Constable Dave Thompson, who said he was becoming 'increasingly concerned' about events at Anderton.

'Views are entrenching with a determination to win this argument,' he warned.

'This is creating an environment where those who seek division will have cause to celebrate and to exploit.'

We'll come back to those individuals. But the wider narrative, highlighted by the ugly episode, is that the row is escalating and spreading beyond Birmingham.

Shakeel Afsar, 32, who describes himself as a private landlord and property developer, has co-ordinated almost daily protests outside Anderton school with his ever-present voice amplifier

Letters opposing the teaching of same-sex relationships, from Islamic organisation Stop RSE (Relationships and Sex Education), have been sent to schools in Bradford, Bristol, Croydon, Northampton, London and Manchester.

Another Islamic outfit is urging Muslims online to join a 'parental action group' and asking for donations to 'protect the value of your children this [holy] month of Ramadan'.

The tragedy is the real victims are the children in whose name this dispute is being fought; scores of pupils, trying to enjoy their half-term this week, must feel frightened and confused by what is going on.

While there may be disquiet — among some non-Muslims, too — about the influence the LGBT lobby exerts in society, there can't be many who have much sympathy with the way the Muslim lobby is aggressively pursuing its own agenda in Birmingham. Its strategy appears to be working.

Currently, the Department for Education encourages primary schools to teach children about different families, including those with gay and lesbian parents, but there is no specific requirement to do so until 2020, when relationships education is due to become statutory in all schools.

At another Birmingham school, Parkfield Community, where protests started several months ago, diversity lessons have been temporarily suspended.

Five other primaries in the city are understood to have postponed the introduction of the programme.

The unrest spread to Anderton — where reading material features such books as My Chacha [uncle] Is Gay and My Princess Boy (who is laughed at because he wears girls' clothing) — more than seven weeks ago.

The majority of pupils, aged three to 11, are of Asian or Asian British Pakistani heritage, and from the predominantly Muslim Sparkhill area.

So, depending on which side of the bitter argument you are on, the head teacher, Sarah Hewitt-Clarkson, either behaved courageously or contemptuously.

What is undeniable is that the backlash against her was swift and vicious. 'We've had "Hewitt-Clarkson is a liar", then "Stand down Hewitt-Clarkson", and now "I'm an Islamophobe," a hater of Islam, and of course I'm not,' she said in a radio interview on Tuesday.

But the noise coming from sections of the Muslim community in Birmingham is being magnified by a small number of so-called 'spokesmen', none of whom with children at Anderton.

One of these 'spokesmen' is Shakeel Afsar, who appeared on ITV's This Morning last week, shortly after clashing with Birmingham MP Jess Phillips outside the school. She accused him of using the campaign to promote his own profile.

But the noise coming from sections of the Muslim community in Birmingham is being magnified by a small number of so-called 'spokesmen' (Shakeel Asfar pictured), none of whom with children at Anderton

Mr Afsar, 32, who describes himself as a private landlord and property developer, has co-ordinated almost daily protests outside Anderton school with his ever-present voice amplifier.

The council issued the father-of-two a Community Protection Warning, telling him to stay away from Anderton.

He ignored it. He could be served with a Community Protection Notice to enforce the ban, which carries a £2,500 fine and a criminal conviction if breached.

Mr Afsar's family is from Kashmir, which is at the centre of a territorial dispute between India and Pakistan. He is now a senior figure in a Kashmir liberation organisation.

In 2017, its 'mother' organisation caused controversy by holding a local rally in honour of a Kashmiri fighter killed in action who allegedly belonged to a group reportedly aligned with Al Qaeda. Mr Afsar denies this.

Around 24 hours before he went on TV, a social media post in which he referred to a police officer as a 'pig', alongside two emojis of a pig's face, was removed from his Instagram page.

Apparently, the officer in question had refused to take 'relevant statements' after a woman had been accused of breaking into one of Mr Afsar's properties.

On the night the men in masks turned up, residents also spotted Shakeel Afsar in the street. It was just a coincidence, he insists; he was only there because he was on his way to the mosque.

A demonstration outside Anderton Park Primary School in Birmingham prompted the school to close early last Friday amid safety concerns

'I have no idea who they were,' he said. 'They certainly had nothing to do with me. I am as upset as anyone else about the incident as that is not what we are about.'

Mr Afsar works in tandem with Amir Ahmed. At the same time, Mr Afsar was making his debut on the This Morning sofa, Mr Ahmed, 54, was being interviewed on the BBC by Victoria Derbyshire.

A few years ago Mr Ahmed, an IT consultant and father of seven (none at Anderton, by the way) was profiled in a book about Muslim Britain in which he expressed concern that drums, trumpets and guitar lessons had been introduced at a school his children attended, Nansen Primary.

This is the feeder school for Park View secondary school, where his children have also gone. These are all instruments deemed 'alien' to Muslim conservative culture.

He also regarded Trojan Horse — the scandal that, in 2014, exposed attempts to impose a hardline Islamic ethos on secular schools in Birmingham — as a smokescreen to 'squash our culture'.

Mr Ahmed was only too happy to restate his views when contacted, and was particularly effusive about Park View: 'There was no radicalism or extremism at Park View. The school was not hardline.'

For the record, Park View was where Department for Education inspectors found girls were made to sit at the back of the class.

While there may be disquiet — among some non-Muslims, too — about the influence the LGBT lobby exerts in society, there can't be many who have much sympathy with the way the Muslim lobby is aggressively pursuing its own agenda in Birmingham

The inquiry into Trojan Horse, led by former counter-terrorism police chief Peter Clarke, revealed how the then head teacher had established something dubbed the 'Park View Brotherhood'.

This closed discussion group suggested that the killing of Woolwich Fusilier Lee Rigby and the bombing of the Boston Marathon were faked.

Mr Ahmed is convinced that Birmingham is 'just the start'. 'The parents won't be backing down,' he said.

'So, if the school doesn't listen then this will escalate. There will be more walkouts, children will be taken out of school for days at a time, and there may well be protests outside the town hall.

'There are other concerned Muslim groups around the country who are watching what is happening in Birmingham. London, Manchester, Leeds, Nottingham, Bournemouth and Brighton — it's all over the country.'

The national campaign includes Muslim convert Dr Kate Godfrey-Faussett, the controversial psychologist behind Stop RSE who is being investigated by her professional body for saying lessons taught in Birmingham were aimed at 'queering' the Muslim community.

Tensions in Birmingham are being inflamed by such rhetoric. But religious conservatism is embedded in districts such as Sparkhill.

Abdul Ghaffar lives in Dennis Road, a few yards from Anderton Park Primary, with his wife and three children who attend other local schools.

His family, originally from Pakistan-controlled Kashmir, run a furniture business.

You could not wish to meet a nicer man than Mr Ghaffar, who is in his early 40s. He could not 'get on better' with the gay couple next door, he tells me, after inviting me into his home. They feel the same way about him, incidentally.

Mr Ghaffar, however, is also fully behind the protests on his doorstep. Indeed, he is proud of the fact he organised the sound system for a recent rally that took place outside Anderton.

'If any of my children turned out to be gay or lesbian I think I would kill myself,' he says. 'That's how embarrassed I would be.'

When I tell him that his gay neighbours were targeted by the men in masks, ex-doorman Mr Ghaffar, who is 6ft 5in, is appalled. 'If I had been here I would have stopped it. No one should have pelted eggs at anyone. It was out of order.'

Mr Ghaffar, it turns out, knows the protester whose comments on Sky News caused outrage recently.

He plays me a clip of the interview. 'God created man and then he created woman for man's pleasure and for his companionship,' the protester declares. 'He did not create man for man.'

His comments were condemned by Anderton head Mrs Hewitt-Clarkson, who tweeted: 'Not this woman, or any of the women in my school, or any of the girls. What shameful words and behaviour that have been invited onto the pavements of my lovely school.'

Mr Ghaffar is acquainted with the man in question from his days on the doors in Birmingham.

'Do you feel the same way?' I ask Mr Ghaffar. 'Yes, I do,' he replies.

Almost all of Anderton's 800 pupils are Muslims, and for Muslims, homosexuality is sinful

Outside, a group of Muslim mothers is handing out leaflets headlined: 'Calling all parents and supporters . . . power lies in your hands, it is your child.'

The school is accused of 'obstructing and undermining our democratic rights' — a recurring theme in this stand-off.

One mum said she had withdrawn her three daughters from Anderton. 'I do not want my daughters to learn about sexuality and LGBT at the age of four and five,' she said.

'That's what these protests are all about. We have said we have nothing against homosexuals but we are still being labelled bigots. I think that's a racist attitude.

'We are prepared to home-school our children. The school can't keep ignoring hundreds of parents and then fine us for not sending our kids to school. They are making this an impossible situation for us.'

One of the few parents who doesn't share those views is Imarah Forrester, 23, a shop worker and non-Muslim whose five-year-old son Harley is a pupil at Anderton. 'All the shouting and large crowds make him scared,' she says.

'I get stared at when I walk past some of the mothers because they know I don't agree with them. It can be quite intimidating.

There have been a few occasions when they have tried to back me into a corner and try to get me on their side but I am too strong-minded to fall for that.'

One exchange in particular sticks in her mind.

'When the protests first started, I was curious as to why they were happening,' she explained.

'The conversation became heated because the lady did not like the fact I was questioning her.

Back in 2015, Mrs Hewitt-Clarkson received a death threat on social media. 'Any head teacher who teaches my children it's alright to be gay will be at the end of my shotgun,' she was told.

The next day, a dead dog was left outside the school, strung up on the railings with medieval brutality.

Now, more than four years on, it is men with skeleton masks.

So much for progress.

Additional reporting: Amardeep Bassey and Mark Branagan