The incident happened in Upper Street near Canonbury Lane just before 8am today (April 10).
Officers and London Ambulance Service crews attended and found four people injured.
Two of them were taken to hospital for further treatment where their conditions are unknown at this stage.
Upper Street is closed both ways between Canonbury Lane and Barnsbury Street as the incident is dealt with.
We have contacted Metropolitan Police for further information.
A spokesperson for London Ambulance Service said: “We were called at 7.57am this morning (Thursday 10 April) to reports of a road traffic collision in Upper Street, Islington.
“We sent a number of resources to the scene, including ambulance crews, a paramedic in a fast response car, an incident response officer and London’s Air Ambulance.
“The first of our crews arrived in one minute.
“Our crews treated four patients at the scene, before taking two to a London major trauma centre and two to hospital.”
