Firefighters were called out to the same job twice after a caravan was found burning in a street.
Officers attended Rutherglen Road in Hylton Red House, at 6.31pm yesterday, to extinguish the blaze.
The fire had destroyed the caravan, while heat damage was caused to a nearby Citroën C4 and a fence.
Firefighters from Marley Park and Sunderland Central community fire stations were then called back out at 7.33pm as the caravan was once again ablaze.
Both fires are suspected to have been caused by malicious ignition.