... These sources are known from a previous study to be associated with dense gas and dust, and not associated with HII regions. All 11 sources were detected in HCO+, 9 in mm-continuum and 5 (out of 8 observed) in cm-continuum. The derived physical parameters confirm the high mass nature of these molecular clumps and suggest they are gravitationally bound. Molecular outflows were detected toward 6 sources, with flow masses and momenta much higher than in low-mass Young Stellar Objects (YSOs). ...