Witnesses have described the scene after a van was driven into pedestrians near a north London mosque, leaving one man dead and eight injured.
According to one man at the scene, the suspect - a 48-year-old who was detained by onlookers before being arrested by police - screamed "I'm going to kill all Muslims" before he was tackled to the floor.
Abdulrahman Saleh Alamoudi said he was among a group of people helping an elderly worshipper who had fallen down, perhaps because of the heat, when the van swerved towards them.
He told BuzzFeed News: "This big van just came and went all over us.
"I think at least eight or 10 people got injured. Luckily I managed to escape. And then the guy came out of his van and I got him.
"He was screaming, he was saying, 'I'm going to kill all Muslims, I'm going to kill all Muslims'. He was throwing punches.
"Then we managed to get him on the floor. Then he was saying, 'Kill me, kill me'. I said, 'We are not going to kill you. Why did you do that?' He wouldn't say anything."
Another witness, Abdikadar Warfa, said he helped to detain the suspect while his friends helped victims.
"I saw a man underneath the van. He was bleeding. My friend said he had to lift the van, I was busy with a man who tried to escape. My friend said he said some words, but I didn't hear it," he said.
"They (people who were hit) were mostly young. They are very bad. I tried to stop him (the suspect), some people were hitting him but I said stop him and keep him until the police came.
"He was trying to run away but people overpowered him. He was fighting to run away."
Mr Salah Alamoudi said he had also helped to hold the suspect on the ground for up to half an hour before police arrived.
"The guy, I had to keep him at least half an hour. He was a strong guy. A big man," he said.
"It was heartbreaking. It wasn't an accident."