A flat was set alight on Bonfire Night after a firework was deliberately thrown through an open window.
Firefighters were called out at 8.15pm on November 5 after the lighted firework was thrown into a ground floor flat in Chesterton Walk, Western Park, Leicester.
Fire crews wearing breathing apparatus tackled the blaze which was in the living room of the flat.
It is believed the flat was empty when the firework was thrown in.
No-one was hurt in the incident.
Police and fire officers are investigating the incident.
A Leicestershire Fire and Rescue Service said: “We received a report at 8.15pm of a flat on fire in Chesterton Walk, Leicester.
“We treated it as persons reported initially but established that the occupier of the flat was not in at the time.
“Firefighters wearing breathing apparatus entered the ground floor flat. The fire was located in the living room area of the property.
“The fire was extinguished.
“Police and fire investigators are investigating the cause.
“It is believed the cause was a lighted firework thrown through an open window.”
Fire crews from Western, Southern and Central station attended the blaze.
The fire service said they had a busy time with Bonfire Night.
They said they were called out to 43 fire related incidents between 7am yesterday and 7am today.
“The majority of those were Bonfire Night related to fires out of control or needing to be checked,” said a spokesperson.
“The flat incident is the only one involving fire at a property.
“Last year, during the same time period we had 25 call outs. So it was busy night last night.”