Londons transport authority said on Twitter that the Seven Sisters road had been closed due to an "emergency services incident".
It is located a short walk away from Emirates Stadium, home of the Arsenal football club in north London.
(Victoria Jones/PA via AP).
(Yui Mok/PA via AP).
Finsbury Park mosque was once a notorious hub for radical Islamists but has entirely changed in recent years under new management.
Speaking to Buzzfeed News, he said: "This big van just came and went all over us".
Deputy assistant commissioner Neil Basu confirmed the man who died was receiving first aid as the attack unfolded.
London's Metropolitan Police said officers were called just after midnight Sunday to an incident on Seven Sisters Road.
On March 22, a man drove a vehicle into pedestrians on the Westminster Bridge in London and stabbed a policeman to death before being shot dead killing five people.
Mr Basu added: "Given the methodology and given what was occurring, what's happened, the tragic incidents across the country, this had all the hallmarks of a terrorist incident".
The investigation into the matter will be conducted by counter-terrorism command.
"Word by word." Police said that one man had been arrested at the scene and that no further suspects had been identified.
Rudd, who is in charge for government law enforcement, said: "Londoners have been hit with a series of attacks and have been nothing short of heroic." she said Monday.
"I will chair an emergency meeting later this morning". He's "been taken to hospital as a precaution", where he'll receive a mental health assessment, according to the statement. "We have worked very hard over decades to build a peaceful and tolerant community here in Finsbury Park and we totally condemn any act of hate that tries to drive our wonderful community apart", a statement read.
"The Met have deployed extra police to reassure communities, especially those observing Ramadan".
The attacker struck as the area was busy with worshippers attending Ramadan night prayers at Finsbury Park mosque.More news: "Manchester United" is ready to make a big offer for Ronaldo
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Mohammed Kozbar said the Muslim community is "in shock".
"So if the victim is Muslim, but the perpetrator is not Muslim, that means it can't be terrorists in the eyes of the mainstream media?"
Video filmed in the immediate aftermath showed a Caucasian man being detained by police.
Someone in the crowd yelled to others not to harm the man while he was taken into custody.
As tempers flared, Mohammed Mahmoud, a 30-year-old imam from the Muslim Welfare House, and a group of people formed a protective ring around the suspect as police bundled him into the back of a van. They are investigating the crash as suspected terrorism.
And eyewitness Hussain Ali, 28, said: "The leader of the mosque said "You do not touch him". No one! No one!"
"We have been informed that a van has run over worshipers as they left #FinsburyPark Mosque", the Muslim Council of Britain tweeted early Monday.
The driver has been arrested on suspicion of attempted murder.
"He has assured me that his team is fully engaged and working in partnership with the London Metropolitan Police as the investigation into the abhorrent attack at Finsbury Park gets under way". Eight others are in hospital and two more were treated at the scene.
Britain's terrorist alert has been set at "severe", meaning an attack is highly likely.
The incident comes after two deadly Islamist-inspired attacks this year that used vehicles to ram pedestrians - a stabbing spree earlier this month in the London Bridge area and a March attack in which a man drove a auto into crowds on Westminster Bridge.
"The driver of the van - a man aged 48 - was detained by members of public at the scene and then arrested by police in connection with the incident".
The force also dismissed reports that the van driver produced a knife, saying: "At this stage there are no reports of any persons having suffered any knife injuries". They must be somewhere around Finsbury Park.
"My prayers are with the victims and their families". The attack comes during the Muslim holy month of Ramzan.
Witnesses said the road was "backed up" with police cars, ambulance and fire engines.
No other details were immediately available.