A fire at a ground floor flat in Preston is being investigated by detectives.
Police say the blaze on Harcourt Street, on Friday night, is being treated as “unexplained”.
Firefighters were alerted by residents in the flat above at around 11.30pm.
Nobody was hurt in the blaze, which left the property badly smoke damaged.
Det Insp Nick Hills, of Preston CID, said: “We are investigating a fire at a ground floor flat that we are treating as unexplained.
“We are appealing for anyone with information to come forward.”
Contact police on 101 or call Crimestoppers anonymously on 0800 555 111.