Two people were arrested in Chesterfield yesterday for alleged drugs offences.
Police were called to Spire Walk Business Park at about 5.15pm on Thursday.
Officers from Derbyshire Constabulary arrested two people and seized cash, drugs and two knives.
There was a heavy police presence at the scene as missiles were thrown at officers from people standing on top of a grass embankment, close to Chesterfield Skatepark.
A spokesman for Derbyshire Constabulary said the arrests were part of an operation to combat the supply of drugs into Chesterfield town centre.
The two people arrested have been released under investigation.