An imam reportedly saved the van driver involved in the suspected Finsbury Park terrorist attack from being attacked by members of the public in the immediate aftermath of the crash.
One person has died and 10 more are injured after a van ploughed into pedestrians near a mosque in north London in the early hours of Monday.
Witnesses reported those nearby grabbed and pinned the driver down until police arrived.
One said the furious crowd might have injured or killed him were it not for the intervention of imam Mohammed Mahmoud.
An eyewitness who gave his name as Abdul told The Independent: "People gather on that part of the street during Ramadan to chat and socialise so it was premeditated. He knew what he was doing.
"He waited until people had come out then drove at the people on the right then swerved to hit people on the left. Someone was lying under his van shouting 'Help me'.
"He tried to run away but we brought him down. He would've died because so many people were punching him but the imam came out and said 'No more punching, let's keep him down until the police come'.
"As he was being arrested he was laughing and smiling and shouting things about Muslims. I don't want to say what but it was but it was the sort of thing that made people want to punch him."
He described the attacker as a tattooed white man in his late 30s or early 40s.
Police said a 48-year-old suspect has been arrested on suspicion of attempted murder, and that they are not looking for anyone else.
Toufik Kacimi, chief executive of the nearby Muslim Welfare House, thanked Mr Mahmoud “whose bravery and courage helped calm the immediate situation after the incident and prevented further injuries and potential loss of life”.
Hamza Nimane, who was in the mosque at the time of the attack, told BBC Radio 4's Today programme: “It wasn't the police that arrested him — it was the people that came out of the mosque.
”They're the ones that grabbed him and managed to hold him down.“
He added: “There were at least 300 people in the mosque praying, and everyone was panicking, everyone was screaming.
“I was looking around me, I saw a few people lying on the floor with blood on their head, and then obviously the ambulance service came and started treating them.
“There was people lying everywhere, basically; I saw at least seven people lying on the floor.
“Some of them even looked dead to me, to be honest, because people were trying to cover them with sheets and stuff.”
Speaking on Monday morning, Metropolitan Police deputy assistant commissioner Neil Basu said the incident was being treated as a "terrorist attack'' and thanked members of the public for restraining the suspect.
He said that a man who died in the Finsbury Park incident was already receiving first aid from members of the public at the time and it is not yet known if his death was caused by the attack.