Police do not believe a recent spate of arsons in the Dearne are linked.
Officers have urged witnesses to come forward following a number of vehicle fires over the last month.
On Monday 28 September, three minibuses at Wath Comprehensive School were set alight, causing extensive damage. A 15-year-old local boy was arrested in connection with the incident and released on police bail.
Last week, emergency services were called to reports of four vehicle fires during the early hours of Thursday 15 October in Church Street, Valley Drive, Vicar Road and Montgomery Square, Wath-upon-Dearne.
One of the vehicles set alight was an unattended police vehicle.
In the most recent incident, between 40 and 70 vehicles were significantly damaged by a fire at a vehicle compound in Manvers Way on Sunday 18 October.
No arrests have so far been made.
Detective Sergeant Iain Martin from Rotherham said: “These fires have caused extensive damage and the total cost of the vehicles damaged is significant.
“It is miraculous nobody has been seriously injured as a result of such reckless behaviour and our officers are actively pursuing a number of lines of enquiry in a bid to identify those responsible for these acts.
“While all three incidents have happened in close proximity, there is nothing to suggest that the fires are linked at this time. However, we are keeping an open mind and I’d encourage anyone with information to get in touch.”
Police remain in the local community carrying out house-to-house enquiries and providing reassurance, as well as examining CCTV footage from the surrounding area.
If you hold any information about any of the incidents that may help officers, please call 101 or email firstname.lastname@example.org, quoting incident number 1179 of 18 October 2015.
Alternatively, you can call Crimestoppers anonymously on 0800 555 111.