Several people were injured in north London early on Monday when a van rammed into worshippers leaving a mosque, witnesses said told Reuters, in what British police described as a "major incident".

The Muslim Council of Britain said the vehicle hit people as they were leaving the Finsbury Park Mosque, one of Britain's largest. The attack comes during the Muslim holy month of Ramadan, when people attend prayers at night, the Reuters reported.

Two worshippers were feared killed, according to the Sun newspaper, but there was no immediate confirmation of this.

Prime Minister Theresa May said her thoughts were with those injured in "this terrible incident". The leader of the opposition Labour Party, Jeremy Corbyn, said he was "totally shocked".

Police said they were called just after 12:20 am Sunday to reports of a collision on Seven Sisters Road, which runs through the Finsbury Park area of the city. They said there were a number of casualties and one person had been arrested.

"From the window, I started hearing a lot of yelling and screeching, a lot of chaos outside. … Everybody was shouting: 'A van’s hit people, a van’s hit people'," one woman who lives opposite the scene told the BBC.

"There was this white van stopped outside Finsbury Park mosque that seemed to have hit people who were coming out after prayers had finished. I didn’t see the attacker himself, although he seems to have been arrested, but I did see the van."

A man leapt out of the van and stabbed at least one person, the Evening Standard newspaper reported, citing witnesses. Reuters could not immediately confirm that report.

The incident comes just over two weeks after three Islamist militants drove into pedestrians on London Bridge and stabbed people at nearby restaurants and bars, killing eight.