The unidentified source IGR J16328-4726 was covered with INTEGRAL observations for a long period ( \sim 9.8Ms ) and was undetectable for most of the time while showing a very recurrent micro-activity with a duration from tens minutes to several hours .
We report the discovery of two strong outbursts started at 53420.65 MJD and 54859.99 MJD respectively , the first with a duration of \sim 1 hour and the second with a lower limit on the duration of \sim 3.5 hours .
Furthermore , the source have been detected in nine other short pointings with significance between 4 and 5 \sigma \ / as well as in a one of the revolution ( during the exposure \sim 130 ks ) at a significance level of \sim 7 \sigma \ / .
The stronger outburst spectrum is well described by a power law model with a photon index of \sim 2.0 and a flux of \sim 3.3 \times~ { } 10 ^ { -10 } ~ { } erg~ { } cm ^ { -2 } ~ { } s ^ { -1 } in the 20–50 keV energy band .
The weaker outburst and revolution spectra show the same spectral shape and different fluxes .
The combined timing and spectral properties observed during the outburst , the recurrent nature of this transient source , the Galactic Plane location , a dynamic range > 170 in the 0.3-10 keV band and > 165 in the 20-50 keV and the presence of a IR star in the error circle of an XRT/Swift pointing are suggesting this source as a member of the class of the Supergiant Fast X–ray Transients .