Firefighters were called out to deal with both blazes.
The first saw a car deliberately set alight at 3.05am on Sunday on Eastern Drive, Arbourthorne. Firefighters from Central fire station attended. They left at 4.15am.
Shortly after, firefighters from Rivelin fire station were called out to a deliberate car fire at 3.40am on Niagara Road, near Hillsborough, where a BMW had been set alight. They were there until 4.20am.