One person died and eight others were injured early on Monday after a van ran over pedestrians in the city’s Finsbury Park locality, the London Metropolitan Police said.

A local imam reportedly saved the driver of the vehicle from being assaulted by an angry mob after the incident. “Imam Mohammed Mahmoud’s bravery and courage helped calm the immediate situation after the incident and prevented further injury and loss of life,” The Guardian quoted the Muslim Welfare House representative as saying.

The driver was later arrested, and authorities are trying to ascertain whether it was a deliberate act or an accident. The police have deployed armed personnel in the area as a precaution. “There was no regret, no emotion, he was just there smiling and blowing kisses,” an eyewitness told The Guardian. “He said, ‘I’ve done what I’m supposed to do’.”

The incident took place on Seven Sisters Road near two mosques. The Muslim Council of Britain reported on Twitter that worshippers leaving the Finsbury Park Mosque were among those injured. The London Ambulance Service tweeted that it had sent “number of resources” to the site after being called in around 12.15 am.

British Prime Minister Theresa May said investigators were treating the incident “as a potential terrorist attack” and that she will hold an emergency meeting on the matter. “All my thoughts are with the victims, their families and the emergency services on the scene.” Counter-terror police are now investigating the incident, The Independent reported.

An eyewitness told CNN that she “saw a lot of people injured”. Another told The Guardian that he was told “two people were stuck under the van” and that the police “were quick to the scene”.

This van collision comes on the back of two similar incidents of pedestrians being run over by vehicles in London. On March 22, a man had mowed people down on the Westminster Bridge – killing five and injuring at least 40 others – while heading to the Parliament building in his car. At least eight people died after a van drove into people near the London Bridge on June 4.