Police seized two quad bikes ridden illegally in Rotherham woods.
Officers spotted the bikes being used in Thrybergh Woods on Saturday.
They were patrolling Thrybergh and Dalton because of complaints about off-road bikers in the areas.
The riders abandoned their bikes and ran off when they saw officers approaching.
A South Yorkshire Police spokesman said: "We have seen an increase in calls from the Thrybergh and Dalton areas, and numerous calls for Thrybergh Woods.
"Whilst in Thrybergh Woods, we must have startled the owners of these two quad bikes as they decided not to stay around and speak with us. The riders actually left their quads and ean into nearby fields.
"We recovered the quads and they were sent to the compound to be recycled at a later date.
"Illegal motorbikes and quads are still a priority and we will continue to patrol areas where these are used."
Call 101 to report culprits.