Police said the 48-year-old man who was driving the van that hit people leaving evening prayers at the Finsbury Park mosque has been arrested and taken to a hospital as a precaution.
The three are shot dead by police after killing eight people - three French citizens, two Australians, a Canadian, a Spaniard and a Briton. Two were treated for minor injuries at the scene.
Cops, who arrived at the scene within 10 minutes, said all the victims of the attack were Muslims.
Here's what we know so far.
"There has been an outpouring of sympathy for all for the recent terror attacks but hardly a whisper on this attack", he said.
No other suspects have been reported or identified, and there were no weapons found in the van.
In the sickening clip, posted to Twitter by a relative of someone at the scene, the suspect is seen blowing a kiss at the camera while sitting in the back of a police van. Police said a man who was driving the auto has been arrested and taken to a.
Witnesses told the Standard he shouted "kill me, kill me, I've done my job" as he was pinned down by onlookers before the arrest was made.
Police have not named the man arrested, but the van bears the logo and phone number for Pontyclun Van Hire in south Wales. The driver would undergo a mental health assessment, police said.
Claims that people were also attacked by a knife-wielding man have been dismissed by police, with a spokesman adding that there had been no reports of anyone suffering stab wounds. "Everybody was shouting: "A van's hit people, a van's hit people", one woman who lives opposite the scene told the BBC.
"Our community is in shock, our thoughts and prayers are with those who have been affected by this", Mohammed Kozbar, the mosque's chairman, said Monday.
The attack kills 22 people - a third of them children - and injures scores more in an attack claimed by the Islamic State group.
- Witnesses saw a man underneath the van.
One bystander Sami Ali said: "There was an elderly woman and a guy trapped under the vehicle, everyone was just trying to help them".
"This was an attack on Muslims near their place of worship", she said in a televised address.
Police will assess the security of mosques and provide any additional resources needed ahead of celebrations marking the end of the holy month of Ramadan, Prime Minister Theresa May announced.
Meanwhile Labour leader Jeremy Corbyn said he was "totally shocked" at the incident, adding: "My thoughts are with those and the community affected by this bad event".