  Observational and theoretical results indicate that low-redshift BL Lacertae
objects are the most likely extragalactic sources to be detectable at TeV
energies. In this paper we present the results of observations of 4 BL Lacertae
objects (PKS0521-365, EXO0423.4-0840, PKS2005-489 and PKS2316-423) made between
1993 and 1996 with the CANGAROO 3.8m imaging Cherenkov telescope. During the
period of these observations the gamma-ray energy threshold of the 3.8m
telescope was ~2TeV. Searches for steady long-term emission have been made,
and, inspired by the TeV flares detected from Mkn421 and Mkn501, a search on a
night-by-night timescale has also been performed for each source. Comprehensive
Monte Carlo simulations are used to estimate upper limits for both steady and
short timescale emission.
