  The Galactic center dust ridge consists of a narrow string of massive
condensations identified in submillimeter dust continuum emission. To determine
whether new high-mass stars are forming in this region, we performed new
observations at 870 $\mu$m with the Atacama Pathfinder Experiment telescope and
at 8.4 GHz with the Very Large Array. We complement our data with recent maser
and mid-infrared results. The ridge's clouds are dark at mid-infrared
wavelengths, indicating the presence of cold, high column density material. In
combination with existing temperature measurements in the dust ridge, we
determined the masses of the largest clouds. The results show that the dust
ridge contains a very massive reservoir of molecular material. We find five
radio sources at 8.4 GHz in the general dust ridge vicinity but outside of the
dust ridge clouds, which are probably all excited by massive young stars, whose
properties we constrain. Our observations exclude the existence of zero age
main sequence stars with spectral types earlier than B0.5 within the dust ridge
clouds. The only indication of ongoing high-mass star formation inside the
clouds are class II methanol masers that are found in two of the clouds. Except
for a weak water maser, found in previous observations, no signs of star
formation are detected in the massive cloud M0.25+0.012.
