The attack comes during the Muslim holy month of Ramzan.
Witnesses said the man was "smiling" and "happy" as he was placed under citizen's arrest.
The leader Britain's opposition Labour Party says he was "totally shocked" by an apparent attack by a van driver which killed one man and eight people were seriously injured outside a mosque.
People gathered to pray on the street following the incident.
The Finsbury Park Mosque saw the attack after the worshippers came out of the Ramadan Prayers.
Prime Minister Theresa May: "This is a awful incident".
The council tweeted that its prayers were with the victims.
He added: "I said, 'tell me why did you try driving to kill innocent people?' When he went into the [police] van he made gestures, he was laughing".
USA cable news networks jumped on the story, which extends a particularly violent spring in the U.K. Earlier this month came a similar vehicular attack on pedestrians on London Bridge followed series of stabbings carried out by ISIS-affiliated assailants. "There was three people in the van". According to the 2011 Census, half the population in the borough is aged under 25 are from nonwhite ethnic backgrounds.
Travellers who did with to use the station were being told to use the Station Place entrance, and not the Seven Sisters Road entrance, which was closed.
The Metropolitan Police confirmed that one man died and Counter Terrorism officers are investigating.
The mosque called it a "callous terrorist attack".
Everybody was shouting, 'A van's hit people, a van's hit people'.
The Muslim Welfare House provided religious and educational services for the local community in and around Finsbury Park.
"If you were interested in targeting a group of Muslims at a mosque that was notorious, this would be the mosque you would do it at". A vehicle struck pedestrians near a mosque in north London.
Brendan Cox, the husband of Jo Cox, said that far right fascists and Islamist terrorists were "driven by the same hatred of difference, same ideology of supremacy [and] use the same tactics". "It wouldn't be odd that you would have large numbers of people breaking their fasts and praying at this time".
Witnesses described how a man yelled "I'm going to kill all Muslims" before the vehicle ploughed into a group of people close to the Finsbury Park Mosque in north London.
The mosque, which today operates largely as a community center, rose to worldwide notoriety in the early 2000s, due to its links with Egyptian-born radical cleric Abu Hamza al-Masri.
The Finsbury Park mosque has been associated with hate preacher Abu Hamza and a number of terrorists including shoebomber Richard Reid who attempted to detonate explosives on a flight from Paris to Miami in 2001. My friend said he said some words, but I didn't hear it. They are very bad. "An advance trauma team from London's Air Ambulance has also been dispatched by vehicle".
"He tried to kill a lot of people so obviously it's a terrorist attack. They were helping on the pavement".
He said: "When I drove past slowly I could count three people on the floor and police were performing CPR on one of them".