  Radio observations over the last two decades have provided evidence that
diffuse synchrotron emission in the form of megaparsec-scale radio halos in
galaxy clusters is likely tracing regions of the intracluster medium where
relativistic particles are accelerated during cluster mergers. In this paper we
present results of a survey of 14 galaxy clusters carried out with the
7-element Karoo Array Telescope at 1.86 GHz, aimed to extend the current
studies of radio halo occurrence to systems with lower masses (M$_{\rm 500} >
4\times10^{14}$ M${_\odot}$). We found upper limits at the $0.6 - 1.9 \times
10^{24}$ Watt Hz$^{-1}$ level for $\sim 50\%$ of the sample, confirming that
bright radio halos in less massive galaxy clusters are statistically rare.
