The Metropolitan Police said that one man was declared dead at the scene after a 48-year-old man drove a vehicle into a crowd of people who were apparently administering first aid to someone lying on the pavement.
A van struck into Muslim worshipers who were leaving two mosques located near each other.
One man was trapped under the van and people tried to lift up the vehicle to free him.
The Archbishop of Canterbury has compared the incident with other recent terrorist attacks, calling it "a crime against God and against humanity".
Describing the horrifying scene which unfolded outside the Islamic centre early on Monday morning, he continued: "All I heard was a banging, then I turned and saw all the shouting and running". According to reports from eye-witnesses, the van ran off the road and swerved onto a sidewalk which had a lot of people that were coming from the special night prayers which are always conducted during the month of Ramadan. "While this appears to be an attack on a particular community, like the awful attacks in Manchester, Westminster and London Bridge it is also an assault on all our shared values of tolerance, freedom and respect", he said. "Nevertheless, we will do absolutely all we can - with our partners - to protect Londoners and our city".
The van "turned left with no indication, with no even like suddenly, just deliberately left, and then just hit the people", Amin said.
Earlier this month, a van veered into pedestrians on London Bridge, setting off vehicle and knife attacks that killed eight people and wounded many others on the bridge and in the nearby Borough Market area.
PICTURE: Police close roads in Finsbury Park, north London, following the attack. "I want to kill all Muslims'".
Prime minister Theresa May condemned the incident and said police are treating it "as a potential terrorist attack". During the later visit, Corbyn said he had been in touch with Downing Street over the response to the attack.
Speaking on Monday morning, the senior national coordinator for counter terrorism, deputy assistant commissioner Neil Basu, said: "Sadly, Londoners are waking to the news of another terrible incident in the capital that has left a number of people seriously injured".
"This is being treated as a terrorist attack", said Metropolitan Police Deputy Assistant Commissioner Neil Basu told reporters.
Other footage appears to show the suspect blowing kisses, waving and laughing in the back of a police van just moments after the horror incident. His attack killed five people. CNN spoke to a man at the company, who said he was the owner but declined to give his name.
"Sending love and prayers to the victims in #FinsburyPark London".
He said: "We've been in the area for the past 40 years and we haven't seen anything like this happen". He called the incident a "horrific terrorist attack". Tens of thousands of events were held up and down the country in celebration of the late lawmaker, who once said "we have far more in common than that which divides us".
Two weeks earlier, a suicide bomber killed 22 people at a concert by American pop singer Ariana Grande in Manchester in northern England.
In March, a man plowed a rented SUV into pedestrians on London's Westminster Bridge, killing four people before stabbing a police officer to death outside Parliament.