Police called it "a major incident". "Immediately after the incident, people were praying for the victims of the attack".
"You shouldn't expect - if you're going for ice cream or late-night breakfast - that you're going to get murdered in the street", she said.
Police said the attacker who drove the van has been arrested on suspicion of the commission, preparation or instigation of terrorism, including murder and attempted murder. Police have not yet confirmed the suspect's identity. He has been taken to a hospital as a precaution.
Speaking at Downing Street, May said police chose to treat the incident as a terror attack within eight minutes of receiving the first emergency call.
"Oh Muslims you need to wake up the war is now starting in your own streets", says one of the messages on there.
London Mayor Sadiq Khan praised Mr Mahmoud for calming the situation.
The attack on Monday hits a community already feeling targeted in the fallout from the London Bridge killings and other attacks blamed on Islamic extremists.
Following so soon after the attacks on Westminster Bridge, Manchester, and London Bridge, the terror attack also brings to mind other hurts.
It is unknown whether this most recent incident will affect the Prime Minister's struggle to form a minority government, which is contingent upon her deal with the DUP. May vowed to provide extra police resources to protect mosques.
London Mayor Sadiq Khan said, "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". Mahmud said he rushed out to find worshipers tending the injured and three men restraining the van driver. "This person was conscious".
ISIS leader Al Baghdadi reportedly killed in Russian airstrike
However, Washington said it was uncertain about al-Baghdadi's death, while western and Iraqi experts doubted the Russian claim. The Russian Defense Ministry said the information about his death was still "being verified through various channels".
The rise in hate crimes directed at Muslims can be linked to increased violence among far-right groups in the U.K. Joe Mulhall, a senior researcher at Hope Not Hate, an advocacy group that aims to challenge mistrust and racism through research, education and public engagement, tells TIME that the British far-right is "going through a period where it is more violent than it has been in some time".
Darren Osborne, who police believe was acting alone, was not known to the security services. Early police caution about declaring the incident to be terrorist-related was interpreted by the community as discriminatory.
Police say it is not yet clear whether the man's death was a result of the attack.
"We found that a group of people quickly started to collect around him, around the assailant and some tried to hit him either with kicks or punches". "People are both scared and angry".
"Sending love and prayers to the victims in #FinsburyPark London. I don't think people understand how much these attacks affect all of us".
The van plowed into the worshippers on Seven Sisters Road, a busy thoroughfare in Finsbury Park, north London, near a Muslim community center and a mosque. After those attacks, the mosque was shut down and reorganized and has not been associated with radical views for more than a decade.
It is located a short walk away from Emirates Stadium, home of the Arsenal football club in north London.
The couple are said to have split, with Osborne reported to have been an unemployed former barman who was recently living in a tent in woodland.
Britain's terror alert level is at "severe", meaning security officials believe an attack is highly likely. Earlier this month, a van plowed into pedestrians on London Bridge, after which three men entered a market wielding knives.
Police officers were at the firm on Monday.