Nine cases of property being stolen from cars were reported to Kalgoorlie Police at the weekend.
The stolen property included laptops, a DVD player, mobile phones, wallets and cash.
In some cases vehicles were left unlocked.
Kalgoorlie Police said offenders would look for softer targets as it became harder to commit burglaries and the public needed to ensure valuable items were not left unattended in vehicles.
Police are sending out crime prevention advice and said many people had started taking more care in securing their homes and reporting suspicious behaviour.
Police are focusing their efforts on identifying the offenders.
Anyone with information is urged to phone Crime Stoppers on 1800 333 000.