WATCH: Chaotic aftermath of London mosque van incident

The chaotic scenes outside a north London mosque that saw worshippers reportedly mown down just after midnight on Sunday, has been captured by a terrified bystander.

Bloodied pedestrians can be seen lying on the ground as police sirens and chilling screams ring out in the area.

Police said there were a "number of casualties" and one arrest following the incident outside the Finsbury Park Mosque on Seven Sisters Road, north of the city.

Bloodied pedestrians can be seen lying on the ground as police sirens and chilling screams ring out in the area. Source: Twitter

A section of Seven Sisters Road remains in lockdown. Source: Twitter

Police said they were called to reports of "a vehicle in collision with pedestrians" at 00:20 am (2320 GMT).

"We have been informed that a van has run over worshippers as they left #FinsburyPark Mosque. Our prayers are with the victims," the Muslim Council of Britain (MCB), an umbrella body, said on Twitter.

Harun Khan, the head of the MCB, said the van had "intentionally" run over people leaving night prayers for the holy month of Ramadan.

An AFP reporter could see a helicopter and many emergency vehicles at the scene, which was closed off by a large police cordon.

A photo on Twitter showing a van at the scene. Source: Twitter/andrejpwalker

Traffic was shut down on a section of Seven Sisters Road, where the incident happened.

"We saw lots of people shouting and lots of people injured," David Robinson, 41, who arrived just after the accident said.

The London Ambulance Service said it had sent "a number of resources" to the scene.

The mosque is near Seven Sisters Road and was once a suspected hub for radical Islamists but its image has changed under new management.

Its former imam Abu Hamza was jailed for life in New York on terrorism charges in 2015.

He preached there from 1997 to 2003 before being jailed for inciting violence. He was later extradited to the United States.

In 2015, the mosque was one of around 20 that took part in an open day organised by the MCB to promote better understanding of Islam following Islamist-inspired attacks in Paris.

Despite the change in leadership and new focus on community relations, the mosque received a string of threatening emails and letters in the wake of the Paris attacks.