A device (1) for detecting and signalling attempts at breaching a continuous inclinable enclosure (2) fixed onto removable support posts (3) secured to a concrete support post (4) is described, said device being characterized in that it comprises:
a) an apparatus (5) able to detect and signal by means of one or more sensors (8) the vibrations which are transmitted to it by a body with which the said sensors (8) are in contact;
b) a housing (6) containing the said apparatus (5) and terminating towards the top in a tubular element (7) with a vertical axis (T-T) able to contain internally without play the bottom end (3i) of a removable support post (3), the inclination of which may be adjusted owing to a locating member (10) containing at least two adjusters capable of modifying the inclination of the removable support post (3) arranged so as to be in contact directly or indirectly with at least one sensor (8) of the said apparatus (5), said housing (6) and the associated tubular element (7) being incorporated in or simply fixed to the concrete of said kerb (4) with the opening of the housing (6) directed upwards.