Two blazes broke out yesterday evening in three hours - one in a Harrow Post Office and the other at a house in Hatch End.
Twelve residents had to be evacuated from their flats when a fire started at Citals in Long Elmes, Harrow, at 6pm. Twenty firefighters from four different stations across north-west London were called to quench the flames, and no-one was injured.
The second fire occured in detached house in Cedars Drive, Hatch End, at 8.25pm, damaging part of the ground and first floors. The property was empty by the time fire crews arrived.
Speaking about the earlier Post Office fire, Mick Dent, station manager at Northolt fire station, explained: "The blaze damaged part of the ground floor shop, which was 60 per cent fire and smoke damaged.
"There was no-one in the shop at the time. We believe the owner-occupier was already in contact by the time the fire brigade turned up and had unlocked the front door.
"Before the arrival of the fire brigade, the police had evacuated approximately 12 residents from surrounding flats.
"We were called at 5.58pm and the fire was under control by 7.05pm and the evacuees were started to be let back in at 20 minutes later."
Mr Dent said he could not comment on the nature or cause of the fire as these are still being investigated by London Fire Brigade.
Multiple people rang 999 to report the second blaze in Hatch End, according to Jules Lloyd, white watch manager at Harrow fire station.
He said: "It was a detached, double-fronted house. It was a fire on the ground floor and a first floor fire; it had spread up to the first floor.
"It was a decent fire: thirty per cent of the ground floor and 30 per cent of the first floor were damaged by smoke."
Nobody was reported in the property when the flames broke out. It took 20 firefighters from Ruislip, Ealing, Harrow and Stanmore just 45 minutes to extinguish the blaze.
Mr Lloyd said: "It was a straightforward house fire. It wouldn't have been arduous."
He did not have information on what sparked the blaze, a fact under investigation by specialist fire officers.