  High-resolution observations from the $Interface~Region~Imaging~Spectrometer$
($IRIS$) reveal the existence of a particular type of small solar jets, which
arose singly or in clusters from a tornado-like prominence suspended in the
corona. In this study, we perform a detailed statistical analysis of 43
selected mini-jets in the tornado event. Our results show that the mini-jets
typically have: (1) a projected length of 1.0-6.0 Mm, (2) a width of 0.2-1.0
Mm, (3) a lifetime of 10-50 s, (4) a velocity of 100-350 km s$^{-1}$, and (5)
an acceleration of 3-20 km s$^{-2}$. Based on spectral diagnostics and EM-Loci
analysis, these jets seem to be multi-thermal small-scale plasma ejections with
an estimated average electron density of $\sim$2.4 $\times$ 10$^{10}$ cm$^{-3}$
and an approximate mean temperature of $\sim$2.6 $\times$ 10$^{5}$ K. Their
mean kinetic energy density, thermal energy density and dissipated magnetic
field strength are roughly estimated to be $\sim$9 erg cm$^{-3}$, 3 erg
cm$^{-3}$, and 16 G, respectively. The accelerations of the mini-jets, the UV
and EUV brightenings at the footpoints of some mini-jets, and the activation of
the host prominence suggest that the tornado mini-jets are probably created by
fine-scale external or internal magnetic reconnections (a) between the
prominence field and the enveloping or background field or (b) between twisted
or braided flux tubes within the prominence. The observations provide insight
into the geometry of such reconnection events in the corona and have
implications for the structure of the prominence magnetic field and the
instability that is responsible for the eruption of prominences and coronal
mass ejections.
