Detectives are investigating the circumstances surrounding an assault and stabbing on Friday evening which are believed linked.
In the first incident two boys assaulted a man in a chemist at a shopping centre on Cheltenham Road in Keysborough, on 13 June about 4.55pm.
The 70-year-old victim was assaulted by the pair when he intervened as they tried to leave the store, with suspected stolen items.
The Dandenong North man was taken to hospital with serious injuries.
In the second incident a 16-year-old boy was waiting at a bus stop in Centre Dandenong Road in Dingley Village when he was approached by what is believed to be the same two boys about 7.15pm.
The Dingley Village teenager was then stabbed in what appears to have been an unprovoked attack.
He was also assaulted as he tried to get away.
The boy was transported to hospital with serious injuries.
Local police, detectives and the Dog Squad quickly converged on the area and searched for the pair, who fled the scene.
Dandenong and Moorabbin Crime Investigation Unit detectives are investigating and have ongoing enquiries to make in relation to the offenders involved.
Anyone with information, or anyone who may have witnessed the incidents or with dashcam footage is urged to call Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppersvic.com.au
