  Using a 2.93 fb$^{-1}$ data sample of electron-positron collisions taken with
the BESIII detector at a center-of-mass energy of 3.773 GeV, which corresponds
to $(8296\pm31\pm64)\times10^3 D^+D^-$ pairs, we search for the baryon and
lepton number violating decays $D^+\to\bar\Lambda(\bar\Sigma^0)e^+$ and
$D^+\to\Lambda(\Sigma^0)e^+$. No obvious signals are found with the current
statistics and upper limits on the branching fractions of these four decays are
set at the level of $10^{-6}$ at 90% confidence level.
