A 16-year-old boy has been arrested after reports that a machete was brandished during a disorder at a park in Dronfield.
Officers were called to Gosforth Fields, in Bubnell Road, at about 18:30 BST on Friday following a disturbance between groups of youths.
Derbyshire Police said one of them waved around what was described as a machete, adding no-one was injured with the knife.
The suspect, from Sheffield, was detained on suspicion of affray, and remains in custody. The machete was seized at the scene, the force added.