  Studies of evolved massive stars indicate that they form in a clustered mode.
During the earliest evolutionary stages, these regions are embedded within
their natal cores. Here, we show high-spatial-resolution interferometric dust
continuum observations disentangling the cluster-like structure of a young
massive star-forming region. The derived protocluster mass distribution is
consistent with the stellar initial mass function. Thus, fragmentation of the
initial massive cores may determine the initial mass function and the masses of
the final stars. This implies that stars of all masses can form via accretion
processes, and coalescence of intermediate-mass protostars appears not to be
necessary.
