Police say one man has been arrested and there have been “a number of casualties” after a van drove into a group of pedestrians outside a North London mosque.
When is terrorism simply a hate crime or an act of violence? Only when it involves Muslims, some have complained.
That's the sentiment after the Finsbury Park attack, where many questioned why media were not referring to it as an act of terrorism.
Prominent UK writer JK Rowling led the way, asking on Twitter why the attacker was referred to as a "white van driver" instead of a "terrorist" in one headline.
But she later deleted the tweet, saying she accepted the headline had been written before charges had been brought against him.
People take part in a vigil at Finsbury Park in north London. Photo / AP
Authorities waited hours before confirming that a van attack that targeted pedestrians near two Muslim places of worship was being treated as a terrorist attack. By then the pressure had already been mounting.
Mohammed Kozbar, chairman of the Finsbury Park Mosque was one of the first to describe it as a terrorist attack, in an interview with The Sun within hours of the incident.
The mosque later released a statement on its Facebook page saying: "We are extremely unhappy with the mainstream media not reporting this as a terrorist attack, whereas they are very swift in describing attacks involving individuals professing to be Muslims and acting in the name of Islam.
"We need fair and balanced reporting from the media; it is completely unacceptable that the media choses to engage in selective reporting."
Others agreed with many on social media also criticising the coverage.
So who's right?
A hate crime is defined as a crime motivated by prejudice, whether it's racial, sexual or otherwise. Terrorism is defined as the unlawful use of violence to intimidate in the pursuit of political aims.
Professor John Blaxland said deciding which is which had become "a real problem" because terrorism had become associated with Islamic acts of mass violence.
"The interesting thing is that we don't know much background (about the attacker), we don't know much about his association with a party or position, so how we go forward in categorising this particular act is fraught," he told news.com.au.
"Because if it's not terrorism, we fall into the trap as only seeing Islamic violence like this as terrorism and that's a problem because it will generate backlash."
While previous acts of terrorism had been defined as such because of the association with Islamic State, Prof Blaxland said authorities had created a rod for their own back in calling these acts terrorism, rather than criminally motivated acts of violence.
Darren Osborne from Cardiff, 47, who is believed to be a father of four, has been identified as the attacker.
Forensic officers move the van at Finsbury Park in north London which struck pedestrians. Photo / AP
Witnesses said the suspect was shouting "I'm going to kill Muslims", and was waving and smiling after he brought carnage to Seven Sisters Road.
The man was initially arrested on suspicion of attempted murder but Scotland Yard said he was later arrested for the commission, preparation or instigation of terrorism including murder and attempted murder.
Prime Minister Theresa May has condemned the incident as "every bit as sickening" as the recent atrocities in London and Manchester. She originally labelled it "a terrible incident" but firmed her wording later.
May said it was a "potential terrorist attack" and a reminder that "terrorism, extremism and hatred take many forms".
London Mayor Sadiq Khan didn't shy away from labelling the act "terror".
"One of the things that all these terrorists share is a perverse ideology that wants to fuel division and divide our communities. We're not going to let them," he said, speaking after prayers at the Muslim Welfare House on Monday evening.
Security Minister Ben Wallace told BBC radio that the suspect was "not known to us".
London police chief Cressida Dick said the incident was "quite clearly an attack on Muslims" and promised a stepped-up police the presence near mosques as the holy month of Ramadan draws to a close.
Ten people were injured in the attack, which took place early Monday near Finsbury Park mosque, north London, raising fears of retaliation against Muslims after recent assaults by Islamic extremists.
The use of a vehicle to mow down pedestrians drew horrifying parallels with this month's London Bridge attack.
In that incident, three men slammed a van into pedestrians before embarking on a stabbing spree - an attack claimed by the Islamic State group.
In March London was hit with another car and knife rampage, that one near parliament. It was also claimed by IS.
This time the attacker deliberately targeted Muslims, according to the police.
"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, head of the Muslim Council of Britain, an umbrella body.
After the London Bridge attack, the mayor's office reported a 40-percent increase in racist incidents in the capital and a five-fold increase in anti-Muslim incidents.
Mohammed Kozbar, chairman of the Finsbury Park Mosque, described the attack as "cowardly".
"Our community is in shock," he said, urging people attending prayers to remain vigilant.
