  In this paper we establish some new congruences involving central binomial
coefficients as well as Catalan numbers. Let $p$ be a prime and let $a$ be any
positive integer. We determine $\sum_{k=0}^{p^a-1}\binom{2k}{k+d}$ mod $p^2$
for $d=0,...,p^a$ and $\sum_{k=0}^{p^a-1}\binom{2k}{k+\delta}$ mod $p^3$ for
$\delta=0,1$. We also show that
$$C_n^{-1}\sum_{k=0}^{p^a-1}C_{p^an+k}=1-3(n+1)((p^a-1)/3) (mod p^2)$$ for
every n=0,1,2,..., where $C_m$ is the Catalan number $\binom{2m}{m}/(m+1)$, and
(-) is the Legendre symbol.
