A van ran into pedestrians near a north London mosque, killing one man and injuring eight others in an incident that police on Monday said was being investigated by counter-terrorism officers.
The 48-year-old driver of the van was detained by members of the public and then arrested by police, as Muslim leaders said worshippers were specifically targeted after leaving prayers at the mosque shortly after midnight.
The incident comes after two deadly Islamist-inspired attacks this year that used vehicles to ram pedestrians — a stabbing spree earlier this month in the London Bridge area and a March attack in which a man drove a car into crowds on Westminster Bridge.
"One man was pronounced dead at the scene... Eight people injured were taken to three separate hospitals," police said in a statement, adding that two other people were treated for minor injuries.
Eyewitness Abdiqadir Warra told AFP: "He just drove at people. Some of them he took a few metres (along the road)."
David Robinson, 41, who arrived just after the accident, said: "We saw lots of people shouting and lots of people injured".
Amateur video footage seen by AFP showed three people lying on the ground, including one who was receiving mouth-to-mouth resuscitation.
Police said the driver had also been taken to hospital and would receive a mental health assessment.
"Due to the nature of this incident, extra policing resources have been deployed in order to reassure communities, especially those observing Ramadan," the police statement concluded.
The Muslim Council of Britain (MCB), an umbrella body for British Muslims, said the incident occurred outside the Muslim Welfare House on Seven Sisters Road, near the Finsbury Park mosque.
Harun Khan, the head of the MCB, said the van had "intentionally" run over people who were leaving prayers held during the holy month of Ramadhan.
Prime Minister Theresa May condemned it as a "terrible incident", while opposition Labour leader Jeremy Corbyn said he was "totally shocked" and had been in touch with mosques and police.
The area is in Corbyn's Islington North constituency.
A helicopter hovered overhead and several emergency vehicles blocked a section of Seven Sisters Road, a busy thoroughfare where the incident happened.
Police, including armed officers, could be seen manning a wide cordon around the area. Others searched the area with sniffer dogs.
A group of Muslim men were praying on the pavement nearby. Traffic was shut down along a one-kilometre section of the road.
Finsbury Park mosque was once a notorious hub for radical Islamists but has entirely changed in recent years under new management.
Its former imam Abu Hamza was jailed for life in New York on terrorism charges in 2015.
He preached there from 1997 to 2003 before being jailed for inciting violence. He was later extradited to the United States.
In 2015, the mosque was one of around 20 that took part in an open day organised by the MCB to promote better understanding of Islam following Islamist-inspired terrorist attacks in Paris.
Despite the change in leadership and a new focus on inter-faith relations, the mosque reported it had received a string of threatening emails and letters in the wake of the Paris attacks.
"If this attack is confirmed as a deliberate terrorist attack then this should be classed as an act of terrorism," said Mohammed Shafiq, head of the Ramadhan Foundation community group.
"The British Muslim community requires all decent people to stand with us against this evil violence," he said, adding that "rampant Islamophobia has been on the rise for a number of years".
Cage, a Muslim human rights group, said there had been "an epidemic rise in anti-Muslim hate crimes" but called for calm "not to inflame an already volatile and distressing situation".
Monday's incident in London follows an Islamist-inspired attack on June 3 in which three militants wearing fake suicide vests ran over pedestrians and went on a stabbing spree in bars in the London Bridge area.
They killed eight people before being shot dead by police.
London Mayor Sadiq Khan said following that attack that there had been a 40-percent increase in racist incidents in the city and a fivefold increase in the number of anti-Muslim incidents.
On his Facebook page, Khan at the time called on Londoners "to pull together, and send a clear message around the world that our city will never be divided by these hideous individuals who seek to harm us and destroy our way of life".
Britain has seen two other attacks this year.
On March 22, a man drove a rented car into pedestrians on Westminster Bridge in London and stabbed a police officer guarding the British parliament to death before being shot dead.
Five people were killed in the attack.
On May 22, a suicide bomber blew himself up outside a pop concert in Manchester, killing 22 people.