Police chase gems worth $20,000 after attack on car at Prahran

Police have made a plea for help following a disturbing brazen attack on a car stopped at traffic lights at Prahran on Tuesday.

Two men, with their faces covered, jumped out of a blue Toyota Corolla during the incident on Williams Road, smashing three windows of another car before stealing a backpack inside the vehicle.

That backpack contained gems valued at $20,000. It?s that fact that has police thinking it was pre-meditated.

?I?d be very confident in saying it was well organised and they were well aware of what they were carrying,? Detective Senior Constable James Howden told Tom Elliott.

Anyone with information is urged to call Crime Stoppers on 1800 333 000 or submit a confidential crime report to www.crimestoppersvic.com.au.

Click PLAY below to hear police speak with Tom Elliott.