  We studied the soft-X-ray emission of five hard-X sources: IGR J08262-3736,
IGR J17354-3255, IGR J16328-4726, SAX J1818.6-1703 and IGR J17348-2045. These
sources are: a confirmed supergiant high mass X-ray binary (IGR J08262-3736);
candidates (IGR J17354-3255, IGR J16328- 4726) and confirmed (SAX J1818.6-1703)
supergiant fast X-ray transients; IGR J17348-2045 is one of the as-yet
unidentified objects discovered with INTEGRAL. Thanks to dedicated XMM-Newton
observations, we obtained the first detailed soft X-ray spectral and timing
study of IGR J08262-3736. The results obtained from the observations of IGR
J17354-3255 and IGR J16328-4726 provided further support in favor of their
association with the class of Supergiant Fast X-ray Transients. SAX
J1818.6-1703, observed close to phase 0.5, was not detected by XMM-Newton, thus
supporting the idea that this source reaches its lowest X-ray luminosity
(~10^32 erg/s) around apastron. For IGR J17348-2045 we identified for the first
time the soft X-ray counterpart and proposed the association with a close-by
radio object, suggestive of an extragalactic origin. In this proceeding we
discuss the results obtained from the XMM-Newton follow-up observations of all
the five sources.
