Police have begun a campaign to target those taking part in hare coursing across Lincolnshire.
Officers will be working with farmers, landowners and gamekeepers as part of Operation Galileo, which will run through the autumn and winter months.
There were more than 900 reports of hare coursing in the county between September 2008 and March 2009.
Anyone caught engaging in the activity will be arrested and their vehicles and dogs seized, police warned.
Pc Nigel Lound said: "A number of letters have already been sent out to known regular offenders warning them that, should they enter Lincolnshire for the illegal purpose of coursing hares, then they will be actively targeted.
"For us to effectively implement this operation it is essential that people living in rural communities work with us by reporting all incidents to the police, so we are aware of the full picture and can therefore increase our effectiveness."