  Despite extensive surveys of extragalactic TeV gamma-ray candidates only 3
sources have so far been detected. All three are northern hemisphere objects
and all three are low-redshift X-ray selected BL Lacs (XBLs). In this paper we
present the results of observations of the three nearest southern hemisphere
XBLs (PKS0548-322, PKS2005-489 and PKS2155-304) with the CANGAROO 3.8m imaging
telescope.
  During the period of observation we estimate that the threshold of the 3.8m
telescope was around 1.5TeV. Searches for both steady and short timescale
emission have been performed for each source. Additionally, we are able to
monitor the X-ray state of each source on a daily basis and we have made
contemporaneous measurements of optical activity for PKS0548-322 and
PKS2155-304.
