  The outer northeastern region of the Small Magellanic Cloud (SMC) is
populated by a shell-like overdensity whose nature was recently investigated.
We analyzed twenty catalogued star clusters projected onto it from Survey of
the MAgellanic Stellar History data sets. After carrying out a cleaning of
field stars in the star cluster colour-magnitude diagrams (CMDs), and deriving
their astrophysical properties from the comparison between the observed and
synthetic CMDs, we found that four objects are not genuine star clusters, while
the remaining ones are young star clusters (11, age $\sim$ 30-200 Myr) and
intermediate-age (5, age $\sim$ 1.7-2.8 Gyr) star clusters, respectively. The
resulting distances show that intermediate-age and some young star clusters
belong to the SMC main body, while the remaining young star clusters are nearly
13.0 kpc far away from those in the SMC, revealing that the shell-like
overdensity is more extended along the line-of-sight than previously thought.
We also found a clear age trend and a blurred metallicity correlation along the
line-of-sight of young clusters, in the sense that the farther a star cluster
from the SMC, the younger, the more metal rich, and the less massive it is.
These young clusters are also affected by a slightly larger interstellar
reddening than the older ones in the shell-like overdensity. These outcomes
suggest that the shell-like overdensity can possibly be another tidally
perturbed/formed SMC stellar structure from gas striped off its body, caused by
the interaction with the Large Magellanic Cloud or the Milky Way.

Astrophysics of Galaxies