Travellers today filmed on CCTV appearing to break open a gate on to a field in Spondon later left the site and apparently moved to Chester Green.
The dozen caravans left the Spondon site, at around 8pm, said police.
Minutes later, the Derby Telegraph received a call from a reader to say a large group of caravans had moved onto Chester Green.
Police are at the scene at Chester Green to "monitor the situation".
At Spondon, CCTV footage filmed by a neighbour showed one traveller appearing to try to use a set of bolt croppers to try to cut the chain locking the gate. When he failed, another man brought out an iron bar, which seemed to be used to snap the chain. The gate was then kicked open by a traveller, and cars and caravans were driven on.
After they later left the site, following the Derby Telegraph putting the footage live, it appeared they moved to Chester Green, where a resident said he saw them drive cars and caravans up on to and over a kerb and on to the Green.
