Eight people were taken to hospital after the "terrorist attack" near Finsbury Park Mosque, police said.
A group of people were helping a man who had collapsed when they were hit by the van just after midnight. The man has died, but it is unclear whether this was as a result of the attack.
A 48-year-old man has been arrested on suspicion of attempted murder.
Police said all the victims of the attack, which took place outside Muslim Welfare House, were Muslim.
Eyewitness Abdul Rahman said the driver had said he wanted to "kill all Muslims" and told the BBC he struck the man and helped subdue him.