  We study quantum interference effects in a two-dimensional chiral metal
(bipartite lattice) with vacancies. We demonstrate that randomly distributed
vacancies constitute a peculiar type of chiral disorder leading to strong
modifications of critical properties at zero energy as compared to conventional
chiral metals. In particular, the average density of states diverges as $\rho
\propto E^{-1} |\ln E|^{-3/2}$ and the correlation length $L_c \propto
\sqrt{|\ln E|}$ in the limit $E \to 0$. When the average density of vacancies
is different in the two sublattices, a finite concentration of zero modes
emerges and a gap in the quasiclassical density of states opens around zero
energy. Interference effects smear this gap resulting in exponentially small
tails at low energies.
