Two babies have been found “visibly shaken and crying” in a dumped car at the centre of a frantic search overnight.

The one-year-old boy and 11-month-old girl were seated in the back of a Kia Picanto found with the engine still running in Boulder, east of Perth, just after 11pm on Thursday.

The car had been reported missing almost an hour earlier.

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“The children, while unharmed, were visibly shaken and crying and were relocated with their mother,” Inspector Mick Kelly said.

West Australian Police launched a search about 10.15pm when the yellow Picanto was reported stolen from a home on Richardson St in Boulder, more than six hours east of Perth in WA’s Goldfields.

By the time the car was found abandoned two roads over on the corner of Ivanhoe and Piesse streets, whoever had stolen it was gone.

“The keys were in the ignition and the motor was running and it was then left unattended,” Kelly said.

“Kalgoorlie detectives will conduct a thorough investigation to locate the persons or persons that have been involved in this incident.

“We believe it’s more of a crime of opportunity. We do not believe it has been a targeted incident with the owner, the mother of the two children.”

Police are not sure exactly when the car was taken, and are working with the “distraught” mum to understand that and why the children were left in the vehicle.

“It’s a timely reminder that there is no excuse for leaving children unattended in any vehicle,” Kelly said, adding whether or not the mother will be spoken to over that is a “matter for our Kalgoorlie detectives”.

The incident comes after a 15-year-old boy stole two cars with children inside in Kalgoorlie in January.

Anyone with information, dashcam or CCTV should contact Crime Stoppers.