For some time now, the question among security officials has not been if terrorists would bomb Britain again, but when.

They got their answer on Monday night.

There have been attacks and arrests in London over recent weeks, but the massacre in Manchester is markedly different. The relative sophistication of the strike and the intended victims (teenagers at a pop concert) has reawakened dark demons here.

Twenty-two people lay lifeless, making this the worst incident of its kind since 2005 — the year four men detonated backpack bombs on the London subway system. The common denominator between the attackers then and now: a British birth certificate and a suicidal belief in ‘jihad’.

In the last 12 years, there have been a plethora of initiatives and think tanks dedicated to asking why someone born and educated here would resolve to blow himself up among as many of his compatriots as possible. The answer to that question will be pondered over, again, for months to come.

For now, the focus is on Manchester. There were fears that Monday’s atrocity would tear the diverse fabric of this society apart. On the surface, the opposite has happened.

Punjabi taxi drivers helped to evacuate the area without charge, Arab surgeons treated victims and Indo/Pakistani restaurants fed the emergency workers for free. These efforts have not gone unnoticed.

On the morning after the attack a demonstration was held by the far-right ‘English Defence League’. It was quickly outnumbered and out-heckled by counter protesters. All week, faith leaders of every cloth — from Scientologists to Sikhs — have been out in force with one message: We will not be divided!

Devotees of Manchester’s other major dogma, football, showed that they weren’t going to be intimidated either. On Wednesday, drunken Man United fans danced on the streets to celebrate their team winning the Europa Cup. Their shirts may have all been red, but their skin colours reflected every race in this cosmopolitan city. The next night an impromptu street party to raise funds for a local hospital attracted hundreds of ravers.

But despite the defiance, things are far from normal here. There have been numerous false alarms of another attack, causing bomb disposal units to be deployed and major buildings to be evacuated. Police officers armed with machine guns can be seen around any corner. One told me that he’d been redeployed from Scotland after the attack. This is a city on edge.

The anxiety is particularly acute among Manchester’s large Muslim community. The BBC Asian Network has spoken to dozens of people who live here. The common themes have been fear and frustration.

Many are worried that their loved ones will be targeted by violent vigilantes. Their concerns aren’t unfounded. Greater Manchester Police have already reported a sharp rise in suspected hate crimes. One case being investigated is an arson attack on a mosque in nearby Oldham.

Naseem Bibi, whose father runs the mosque, told us: “We’re not answerable for every individual. Everybody is sickened by what happened [at the Manchester Arena]. We’re just human like everybody else.”

Her exasperation was echoed by Irfan Chishti, the Imam of Manchester’s largest mosque. On the eve of Ramazan he fought back tears during an emotional sermon. “He [Salman Abedi] might have had a Muslim name, but we disown his actions. We disown his character. We disown his behaviour. We, as Muslims, have nothing, nothing, NOTHING to do with violence and terror!”

Amir Khan, the former world champion boxer of Pakistani heritage, was in attendance. He told me: “It puts us all on our back foot. We’re going to be walking the streets and people are going to be pointing fingers at us saying we’re terrorists. We all have to stick together and obviously stop things like this from happening. If someone ever has the idea that someone is trying to plot something, we have to go and report it to the police or report it to the community, because this is something that we’re all against.”

Of course, such sentiments are expected in the aftermath of terror attacks. Observed silences and rousing speeches of defiance have become depressingly cliché. What else can one do? But those who go out of their way to lay flowers and speak to journalists are, by virtue, a self-selecting crowd. The concern is not over these individuals.

Even before Salman Abedi’s act of barbarism, more than a dozen young Muslims in Manchester have heeded the call of ‘jihad’ in recent years. How many more could there be?

Rickin Majithia is an Impact Reporter for the BBC’s Asian Network. He tweets at @rick_maj.

You can listen to the BBC Asian Network special from Manchester here: http://www.bbc.co.uk/programmes/b08qmd9q