  We study the expansion dynamics of harmonically trapped bosons in a
two-dimensional lattice within the extended Bose-Hubbard model. We evaluate the
dynamics of the system following a sudden removal of the confining potential,
starting with a cloud mostly in n = 1 Mott state. We show that the nearest
neighbour interactions have a strong influence on the dynamics of ultracold
bosons on an optical lattice. Also we conclude that validity of the widely used
contact potential approximation is questionable in the presence of Feschbach
resonances.
