In a city on edge over a series of Islamist-inspired attacks, where police keep extensive watchlists and monitor potential militants, terror took a new turn when a van ploughed into a group of Muslim worshippers in London on Monday.
A man identified as Darren Osborne, a 47-year-old Welshman from Cardiff, was allegedly behind the wheel. He was not an any security watchlists. But if he took the authorities by surprise, the act capped a growing dread in London's Muslim community.
Witnesses said the driver was heard shouting after he was wrestled to the ground that he wanted to kill Muslims. It was chilling but not, in the Finsbury Park neighbourhood, entirely unexpected. Fears have been growing among Muslims that they could be singled out by extremists in tit-for-tat attacks because of other attacks carried out in the name of Islam, even though they are widely denounced by the mainstream Muslim community.
Monday's attack was confounding in another way, too. Using vans, trucks or cars as weapons poses huge challenges to public safety. Hours after the London attack, a man in Paris drove his car, which contained arms and explosives, into a police car. Only the attacker died, but it underscored the difficulty of defending against incidents involving vehicles. The Paris assailant had not been publicly identified yesterday but was known to French authorities and was listed in a dossier of people suspected of posing a threat to national security.
In England, an attack by a man who was on no one's radar has deepened the anxiety, especially as he appears to have targeted Muslims.
"We don't feel safe anywhere," said a young man who gave his name as Adil Rana. "We don't feel safe walking the streets or going to the mosque."
The incident occurred in Finsbury Park, for years considered to be a hotbed of Islamist extremism. A relatively deprived immigrant neighbourhood in north London, it is the home of the Finsbury Park Mosque - once notorious for housing the radical Egyptian cleric known as Abu Hamza al-Masri, who was later extradited to the United States and found guilty of terrorism charges.
But like many of its surrounding neighbourhoods, the area has rapidly gentrified in recent years, arguably becoming both more diverse and tolerant at the same time. Kebab shops sit comfortably next to cafes serving flat whites.
Finsbury Park Mosque has undergone its own dramatic reforms over the previous decade, too, with its extremist edges stripped away.
For the past decade, the mosque has sought to emphasise, according to its website, the "true teachings of Islam as a religion of tolerance, co-operation and peaceful harmony amongst all people who lead a life of balance, justice and mutual respect". In 2014 it won a prestigious award for its services to the community. But its past links to extremism have made it - and its neighbourhood - a target for criticism from Britain's far right.
Even before this attack, Muslims said they have seen a sharp rise in hate crimes, in London and elsewhere in Britain.
"Over the past weeks and months, Muslims have endured many incidents of Islamophobia, and this is the most violent manifestation to date," said Harun Khan, secretary general of the Muslim Council of Britain, in a statement.
At least 10 people were injured when the van hit the crowd of worshippers who had just left a Ramadan prayer service at the Muslim Welfare House, in Finsbury Park. One man died at the scene, but police said he was receiving first aid before the van struck, and it was unclear whether he died as a result of the attack.
The driver was subdued by the outraged group, but one of the mosque imams appealed for calm, possibly sparing him serious harm.
Imam Mohammed Mahmoud said he then flagged down a passing police car and told the officers: "There's a mob attempting to hurt him. If you don't take him, God forbid he might be seriously hurt."
Rana, who witnessed the incident, said the attacker tried to taunt onlookers as he was arrested.
"He said, 'I'd do it again'," Rana said. "It was a premeditated attack. He picked this area well, and he knows Finsbury Park is predominantly a Muslim area."
Many Muslims feared possible copycat attacks, urging extra security for mosques and other sites. East London Mosque, one of the city's largest, said it was evacuated on Monday after receiving a fake bomb threat. Neil Basu, a London police official, told reporters the case was being treated as a terrorist attack. The suspect was arrested on terrorism charges as well as attempted murder.
British Prime Minister Theresa May met with members of the Muslim community yesterday and said Monday's attack was "every bit as sickening" as previous attacks.
London Mayor Sadiq Khan, the city's first Muslim mayor, called the incident a "horrific terrorist attack," which was "clearly a deliberate attack on innocent Londoners, many of whom were finishing prayers during the holy month of Ramadan.
"While this appears to be an attack on a particular community, like the terrible attacks in Manchester, Westminster and London Bridge, it is also an assault on all our shared values of tolerance, freedom and respect," he said.