That follows a spate of ''petty crime'' - mainly burglaries and breaking into cars - over the past two or more months, which Sergeant Tony Woodbridge attributes to ''about seven or eight'' 12-to-17-year-olds.
''But they are not petty crimes to those who have been victimised. Even the damage is costly,'' he said yesterday.
He appealed to the community to report young people wandering streets after dark, particularly late at night or early morning.
''If they [young people] are not doing anything, then they have nothing to worry about.''
Sgt Woodbridge did not believe the teenagers were an organised gang. Most of the crimes were spur-of-the-moment, taking advantage of an opportunity.
Police and youth aid would work with parents but if they were not satisfied with the action being taken, Child, Youth and Family would be notified.
Police could also ''come down hard'' and charge teenagers.
''It is not acceptable to have young people wandering streets after dark, particularly late on cold nights.''
Taken during the crimes was alcohol, if it was there, as well as cash or smaller items which could be readily sold.
It was believed the proceeds were being used to have people aged over 18 buy alcohol for the minors. Already one person had appeared in court for supplying liquor to minors.
The latest incidents believed attributable to the teenagers were four cars broken into on the South Hill on Wednesday night - two at Oamaru's unofficial car sales yard at Awamoa Park and one each in nearby Hayle St and Arrow Cres.
A Mazda 323 in Arrow Cres was pushed down the road into another driveway and found with doors open.
Items were taken from the cars.
Police found some evidence which was being used for the investigation.
About 4am, two teenagers, aged 14 and 15 years, were stopped by police in the area and taken home to parents.
Sgt Woodbridge believed it was ''highly probably'' those crimes were linked to two cars left at Awamoa Park broken into on Tuesday or Wednesday night, one being stolen and crashed south of Oamaru.
Links between other burglaries and crimes from the Oamaru Harbour area and on the South Hill were being investigated.
