Police do not believe two arson attacks on cars in Antrim town late on Sunday night are linked.
Five cars in total were burnt out across Northern Ireland on Sunday – three in Antrim town, one in Londonderry and one in the Carnmoney area of Newtownabbey.
In Antrim, one car was set on fire in Tower Way shortly before 10.40pm.
Another parked in Hollowburn Road in Ballycraigy was attacked less than an hour later.
A PSNI spokesman said: "The two incidents are not believed to be linked and police are working to establish a motive for both incidents."
The first attack on Sunday happened in Carnmoney shortly before 12.35am.
In the Ballycraigy area of Antrim a car was torched shortly after 1.45am on Sunday, close to houses at Craighill.
In Derry, police are investigating an arson attack on a vehicle in Galliagh at 7.30am.
No one is believed to have been injured in the attacks.
Police are appealing for witnesses.