Officers investigating the arson attack on several cars and a house are appealing for information.
Five cars and a house were devastated during the fires in Horden in the early hours of Tuesday morning.
At around 1.05am police were called to reports of a Hyundai on fire at Seventh Street, Horden.
Three crews from County Durham and Darlington Fire and Rescue Service also responded and on arrival three cars were alight, a Hyundai, Audi A3 and a silver Vectra.
The window of a nearby property, which was unoccupied, had also been damaged.
Although firefighters were able to extinguish the three cars which were ablaze, a further two vehicles were damaged due to the heat.
Detective Constable Rachael Austin Teasdale from Peterlee CID said: “We are currently treating the incident as arson, we need information to help identify those responsible.
“We would like to reassure the public that all information received will be treated with the strictest confidence.”
A spokesman for County Durham and Darlington Fire and Rescue Service, said two crews from Peterlee were initially sent to the scene, followed by one from Seaham.
He said: "Firefighters worked for over an hour to bring the car fire under control.
"Fortunately there were no reported injuries and a joint investigation with Durham Constabulary has been launched into the cause of the fire.”
Pat Barnett, chairman of Horden Colliery Residents' Association, said: "It's really, really awful.
"We've worked really hard with the police and Durham County Council to make the village a good place to live in.
"It's a sad day for Horden.
"We finally got the people that matter looking at what is going on in Horden, and then this happens.
"It destroys your faith in human nature. It's a tragedy.
"We need to get to the bottom of this, because it's going from breaking fences to breaking windows and now setting fire to cars and houses. That's a big step.
"We've got to get the control back to the parents, police and authorities."
Anyone with information with regards to the arson, or anyone who saw any suspicious activity in the area at the time, is asked to contact police on 101, quoting reference number 14 of January 9.