Investigators are probing a suspicious fire that broke out in a block of flats on Saturday morning.
Firefighters were called to Cowan Court, in Ayres Crescent, Stonebridge, at 10.12am after receiving reports of two separate blazes in the stairwell on the top floor of the property.
Police believe the fires may have been started by arsonists and are appealing for information.
DS Garry Morris, Brent CID, said: "Both these fires were started on the stairwell of the flats. We are keen for anyone who may have witnessed the incident to come forward and speak to us so we can piece together exactly what happened and how these fires were started."
A resident was taken to hospital suffering from smoke inhalation, but was later discharged.