What made Dublin, one of the most welcoming cities on earth, explode in anti-migrant violence?

It was a night of shame for one of the most welcoming countries in the world. Ireland was left reeling after as many as 500 thugs responded to a horrifying knife attack on schoolchildren in Dublin on Thursday by launching an anti-migrant rampage.

Fuelled by online misinformation and unsubstantiated rumours that the person behind the attack – which saw three children and a woman injured – was a foreign national, the mobs gathered close to some of the city's most iconic locations, some waving flags and brandishing signs reading 'Irish Lives Matter'.

Shocking scenes saw police officers attacked, with around 50 sustaining injuries – one of whom faces having a toe amputated – while buses and a tram were torched, with one driver punched and dragged from his cab.

As the violence escalated, some of the rioters started a fire on the ground floor of a Holiday Inn Express following rumours that migrants were staying there. Others reportedly petrol-bombed a nearby refugee centre, with fire crews who responded 'pelted with projectiles' and beaten with iron rods.

And in a grim echo of the rioting which blighted English city centres in August 2011, masked youths seized the outbreak of anarchy to smash store windows and strip them of designer trainers and sporting goods.

Armed police were even dispatched to Irish PM Leo Varadkar's Dublin home after calls on extremist messaging sites for rioters to descend on it, the Irish Times reported.

An intensive all-night clean-up operation saw O'Connell Street, one of Dublin's best-known thoroughfares, return to an appearance of normality yesterday.

But despite reassurances that it was 'safe to come into the city', dozens of businesses chose to close their shutters and missed out on lucrative Black Friday sales.

One hotel manager said he received ten times the number of usual cancellations. 'Now that could just be a moment in time, but the world has seen Dublin on fire,' Paul Gallagher said.

While migrant communities said they were fearful for their safety, with some parents pulling their children from school.

A Muslim-run soup kitchen, where many female volunteers wear veils, shut amid safety fears. Founder Lorraine O'Connor said: 'We don't want anybody to be an easy target. We just don't want any more suffering.'

She added that Muslim migrants were were as outraged by the 'barbaric act' as the wider community. 'But because they say he's Muslim, we have to carry the weight of this on our shoulders, and we shouldn't because, in our eyes, as much as the Irish community are mourning for the hurt and pain of them children and their poor families, we are too.'

Last night, the five-year-old girl stabbed in the chest and a school care assistant who 'used her body as a shield' in an attempt to protect children from the attacker remained in a critical condition in hospital.

Meanwhile, 32 people appeared before court after being arrested on Thursday night. Twenty-eight men and four women are facing various charges including theft and public order offences.

While the senseless violence was roundly condemned, warnings were growing that Ireland's political establishment was failing to heed concern at soaring immigration.

On a visit to Dublin, Northern Ireland Secretary Chris Heaton-Harris said 'mainstream politicians' needed to 'articulate' such worries, or risk leaving 'a vacuum for other people who might not be as benign as we are'.

In recent years, soaring numbers of migrants, many of them accommodated in poor areas of central Dublin or small provincial towns, have put acute pressure on Ireland's housing and public services.

A total of 141,600 immigrants arrived in the Republic in the 12 months to April, the highest level since 2007, of whom almost 42,000 were from Ukraine.

And unlike in the UK, where families displaced by Vladimir Putin's invasion were initially accommodated by private individuals, in Ireland they have been put up by the State in hotels and empty office blocks.

In Dublin, huge numbers of foreign nationals have been housed in predominantly working-class areas, where the arrival of unemployed single men can create social friction.

Across the country, a worsening housing crisis and an acute shortage of rental properties, particularly in Dublin and Cork has resulted in a profound change which has severely tested the image of Ireland as a welcoming country.

The upshot has been that an initially warm welcome for refugees has been replaced by mounting tension, with at least 300 anti-migrant demonstrations documented before Thursday's violence.

In one particularly ugly incident back in January, an angry mob of about 200 surrounded a police station in Finglas, a working-class district of Dublin, after rumours spread on social media that a local girl had been raped by a man who had recently arrived in the country.

Just over 14 per cent of the Republic's 5.2million population - 757,000 people – are now non-Irish citizens.

But recent polls suggest that 75 per cent of people believe that the number of refugees Ireland is taking in is 'now too many'.

In a bitter irony, it emerged yesterday that one of the heroes of Thursday's attack on the schoolchildren was himself a recent immigrant.

Brazil-born Caio Benicio, 43, was making a Deliveroo delivery when he witnessed the bloodbath, jumping off his moped and battering the knife-wielding assailant to the ground with his helmet.

'When I saw the knife, I stopped my bike and I just acted by instinct,' he said yesterday.

Downplaying his own courage, the father-of-two paid tribute to a creche worker who was left in a serious condition as she tried to shield the terrified youngsters, describing her as 'very, very brave'.

And he said the anti-migrant anger which erupted hours later 'doesn't make sense because I'm an immigrant myself and I was the one who helped out'.

An online fundraiser asking supporters to 'buy a pint' for Mr Benicio quickly topped £20,000.

Ireland's police commissioner Drew Harris initially blamed the rioting on a 'lunatic, hooligan faction driven by a far-Right ideology'.

Denying that the horrific scenes were proof of a failure of policing, he insisted yesterday 'we could not have anticipated that in response to a terrible crime, the stabbing of school children and their teacher, that this would be the response'.

Meanwhile, last night it emerged that the suspect in the quadruple stabbing was arrested earlier this year for possession of a knife.

The man, originally from Algeria, previously faced deportation proceedings but eventually received Irish citizenship a decade ago.

He was taken to court over the knife incident in May but the Daily Mail understands that he was not convicted due to issues over his mental health. He was last night under police guard in hospital.

One source said there was 'a real possibility' that the stabbing was 'related to a mental health episode due to his history'.

But having initially dismissed a terrorism connection to the stabbing, police chiefs said yesterday they were not ruling out any motive.

More than 30 people arrested during the riots appeared in court yesterday charged with theft and public order offences as well as misusing drugs.

With damage put at tens of millions of pounds, a political fallout saw opposition politicians demand the resignations of Police Commissioner Harris and Helen McEntee, justice minister in the Dublin government.

Amid fears of further nights of violence, the Garda police force took the extraordinary step of borrowing two water cannons from their Northern Irish counterparts. Several Dublin schools closed early on police advice.

Meanwhile, critics have rounded on Ireland's political elite saying it has failed to address the concerns felt by voters, instead smearing them as racist extremists. Two of the three major political parties are currently in coalition, while the third, Sinn Fein, is even more liberal on immigration.

The cosy consensus has helped fuel fringe anti-migrant groups –around 200 protesters gathered outside the Irish parliament in September, shouting racist abuse. The 'fascist-like' scenes prompted one Left-wing political party to warn that Ireland could no longer assume it would 'remain immune to far-Right developments in the rest of the world'.

As recently as Sunday, Mr Varadkar – arguably the country's most visible illustration of the positive side of immigration as the son of an Indian-born doctor – sought to address concerns about migrant numbers. But he insisted: 'Migration is a good thing for Ireland.'

Condemning the rioters yesterday for falsely portraying themselves as patriots, Mr Varadkar said being Irish meant 'more than saluting the tricolour, beating your chest and pointing to where you were born'.

'It means being true to our own history and it means acting with compassion for others.'

He slammed Thursday night's 'warped' mob, saying they 'brought shame on Dublin' and accusing them of being 'filled with hate'. And he pledged new legislation to 'reclaim Ireland from the unscrupulous who prey on the fears of those easily led into darkness'.

Members of Rishi Sunak's Cabinet, in Dublin for a scheduled meeting of the British-Irish Council, also spoke of their shock, with Levelling Up Secretary Michael Gove saying it was 'a mark of Ireland that there's been near-universal revulsion at what happened'.

But Northern Ireland Secretary Chris Heaton-Harris issued a word of warning, saying it was important for elected politicians to 'articulate' the concerns of their electorate if the rise of far-Right extremism was to be combated.

He called for a 'proper debate' about how migration can bring in 'what we need in skills' as well as 'what pressures it brings to our domestic services'.

'These need to be articulated by mainstream politicians because if we don't articulate them then we do leave a vacuum for other people who might not be as benign as we are,' he added.