  The {\gamma}-ray strength function and level density in the quasi-continuum
of 151,153Sm have been measured using BGO shielded Ge clover detectors of the
STARLiTeR system. The Compton shields allow for an extraction of the {\gamma}
strength down to unprecedentedly low {\gamma} energies of about 500 keV. For
the first time an enhanced low- energy {\gamma}-ray strength has been observed
in the rare-earth region. In addition, for the first time both the upbend and
the well known scissors resonance have been observed simultaneously for the
same nucleus. Hauser-Feshbach calculations show that this strength enhancement
at low {\gamma} energies could have an impact of 2-3 orders of magnitude on the
(n,{\gamma}) reaction rates for the r-process nucleosynthesis.
