An investigation is set to get under way after a fire destroyed two cars.
Firefighters from Peterlee were called to Greenside Avenue in Horden at 12.50am today after the blaze was spotted.
It is believed the fire started from an Audi A3 and then spread to a Vauxhall Astra parked next to it.
The cause is suspected to be malicious.
One firefighter wearing breathing apparatus and a hose reel were used to extinguish the fire.
Anyone with information is asked to contact Durham Constabulary on 101 or Crimestoppers anonymously on 0800 555 111.