  K-band spectra of young stellar candidates in four southern hemisphere
clusters have been obtained with the near-infrared spectrograph GNIRS in Gemini
South. The clusters are associated with IRAS sources that have colours
characteristic of ultracompact HII regions. Spectral types were obtained by
comparison of the observed spectra with those of a NIR library; the results
include the spectral classification of nine massive stars and seven objects
confirmed as background late-type stars. Two of the studied sources have K-band
spectra compatible with those characteristic of very hot stars, as inferred
from the presence of Civ, Niii, and Nv emission lines at 2.078 micron, 2.116
micron, and 2.100 micron respectively. One of them, I16177 IRS1, has a K-band
spectrum similar to that of Cyg OB2 7, an O3If* supergiant star. The nebular
K-band spectrum of the associated UC Hii region shows the s-process [Kriii] and
[Seiv] high excitation emission lines, previously identified only in planetary
nebula. One young stellar object (YSO) was found in each cluster, associated
with either the main IRAS source or a nearby resolved MSX component, confirming
the results obtained from previous NIR photometric surveys. The distances to
the stars were derived from their spectral types and previously determined JHK
magnitudes; they agree well with the values obtained from the kinematic method,
except in the case of IRAS15408-5356, for which the spectroscopic distance is
about a factor two smaller than the kinematic value.
