  A Chandra observation of the isolated hard X-ray source XMMU
J061804.3+222732, located in the region of apparent interaction of the
supernova remnant IC 443 with a molecular cloud, resolved the complex structure
of the source in a few bright clumps embedded in an extended emission of a ~ 30
arcsec size. The X-ray spectra of the clumps and the extended emission are
dominated by a hard power-law component with a photon index of 1.2--1.4. In
addition, we see some indications of an optically thin thermal plasma of a ~
0.3 keV temperature. The observed X-ray morphology and spectra are consistent
with those expected for an isolated supernova ejecta fragment interacting with
a dense ambient medium. A possible alternative interpretation is a pulsar wind
nebula associated with either IC 443 or another SNR, G189.6+3.3.
