Three teenagers have been arrested on suspicion of setting a fire at a house in Shirebrook.
Police and firefighters were called to a large blaze at an empty house in Patchwork Row just after 3.20pm on Sunday, September 8.
Following a joint investigation between the emergency services, the fire is being treated as arson.
A Derbyshire Police spokesman said: "Today we arrested three boys, aged 13, 15 and 17, and they remain in custody and are being questioned.
"Although arrests have been made we are still appealing for witnesses.
"We want to hear from anyone who was in the area of Patchwork Row at the time, or who may have been travelling in the area of Market Place, Patchwork Row and Carter Lane between 3pm and 3.20pm and has dashcam footage.
"Anyone with information should contact Derbyshire police using any of the below methods, including reference number 19*481338 in any correspondence. The officer in the case is PC Ashley Taylor."