Police Commissioner Grant Stevens has issued a warning for those in South Australia targeting drivers with Victorian number plates.

Claims of harassment on the roads have been reported throughout the state, with Commissioner Stevens warning South Aussies that anyone targeting Victorians will be dealt with using the full extent of the law.

Under current rules, there are still essential workers permitted to cross the border from Victoria.

Currently, workers in commercial transport, freight services, emergency services, defence, agricultural and primary industries are classified as essential and can be granted permits to enter SA.

Industry body Business SA has said that it has received reports of some truck drivers being spat on, with others having their vehicles damaged.

Reports have also surfaced of truck drivers having their vehicles smeared with dog faeces and being denied access to toilets at service stations.