Detectives are appealing for information after a suspected arson attack in Accrington.
Officers were called around 4pm on Friday, July 8, following reports of an incident in Derby Street.
A fire had started in the basement of a terraced property causing significant damage.
Firefighters from Hyndburn, Darwen and Burnley attended to help extinguish the blaze.
No-one was injured.
Following investigation by Lancashire Police and Lancashire Fire and Rescue, officers believe the cause of the fire to be suspicious.
A 35-year-old man from Accrington was arrested on suspicion of arson and bailed to August 26.
Police are appealing for information and are keen to speak to anyone who can help with enquiries.
Det Con Amanda Bleazard, of Lancashire Police, said: “The fire spread quickly throughout the basement area of the property and it was very fortunate no-one was inside the house at the time of the incident.
“Thanks to the work of firefighters the blaze was put out quickly.
“However, there was a real danger the flames could have spread to other terraced properties and we are thankful for the fire service’s fast response.
“While we have made one arrest, we are appealing for information from the public to help with our investigation.
“We would be keen to speak to anyone who saw any suspicious behaviour in the Derby Street area before the fire was reported, particularly between 3pm and 4pm.
“This fire caused thousands of pounds of damage and we need to find those responsible.
“If you can help, please contact police immediately.”
Anyone with information is asked to contact police on 101 quoting log reference 480 of July 7.