A police probe is underway after two cars were set alight on a Barnsley street.
The vehicles were parked in the Dobie Street area of Worsbrough when they were fired at around 3am on Monday.
A third vehicle was also damaged around the same time.
Police want to trace a man and woman who were seen in the area at the time the offences were committed.
A South Yorkshire Police spokeswoman said: "Police in Worsbrough are appealing for witnesses after a series of incidents over the bank holiday weekend.
"At around 3am on Monday two vehicle fires and damage to a third vehicle were reported in the Dobie Street area of Barnsley.
"The cars sustained damage and it is believed the fires were deliberate.
"Witnesses report seeing a slim male dressed in light clothing with dark hair, and a female in a light-coloured short dress carrying black shoes, in the area at the time of the offences.
"Enquiries are ongoing in the local community."
Anyone with information should call South Yorkshire Police on 101.