Fabian Ali and Mohammed Mohidn, who witnessed the attack outside a London mosque, say one of the men looked "cracked off his face".
The incident happened when a van was driven at high speed into pedestrians near a mosque where Muslims had been praying, killing one person and injuring 10. All of the victims were Muslim, according to police.
The 48-year-old suspect mowed down pedestrians outside a mosque on Seven Sisters Road in Finsbury Park.
Locals held onto the suspect until he was detained by police and later arrested on charges of "the commission, preparation or instigation of terrorism including murder and attempted murder". And the guy was shouting, basically he was saying, "it's our turn, this is for the people [that] you killed earlier".
"We stopped all forms of attack and abuse towards him that were coming every angle, and by coincidence while the people who were tending to the injured were calling emergency services, a police van drove past so we flagged them down".
He said a passing police van was the first on the scene.
The city's Mayor Sadiq Khan, also paid tribute to the religious leader and the local community who apprehended the attacker near the mosque, keeping him safe from mob violence.
The London police are also investigating whether the person who died was actually killed in the attack.
Several injured in London after reports of vehicle ramming pedestrians
Eyewitness Abdulraman Aidroos told Anadolu Agency the "white British man" had shouted "I am going to kill Muslims". Vehicles have also been also used to attack the public on London's Westminster Bride, in Nice, and in Berlin.
Earlier this month on London Bridge, attackers used a vehicle and then knives to kill eight people and wound many others on the bridge and in the nearby Borough Market area.
"Hatred and evil of this kind will never succeed", she said.
Describing the attack, Hussein Ali told news.com.au that Osborne "chose to get as much casualties as possible; he came exactly at the time to get as much people as he wanted".
"One man was pronounced dead at the scene".
"This is an appalling attack on a wonderful, happy, integrated community here in London".
"Like the bad attacks in Manchester, Westminster and London Bridge it is also an assault on all our shared values of tolerance, freedom and respect", he said in a statement.