  We present the results of VLA observations in the ground-state hydroxyl (OH)
transition at 1720 MHz toward 20 supernova remnants (SNRs). We detect compact
emission from four objects. For three of these objects (G32.8-0.1, G337.8-0.1,
and G346.6-0.2), we argue that the emission results from masers which are
shock-excited due to the interaction of the SNR and an adjacent molecular
cloud. We observe a characteristic Zeeman profile in the Stokes V spectrum,
which allows us to derive a magnetic field of 1.5 and 1.7 mG for G32.8-0.1 and
G346.6-0.2, respectively. The velocity of the masers also allows us to
determine a kinematic distance to the SNR. Our criteria for a maser to be
associated with an SNR along the line of sight are that the position and
velocity of the maser and SNR must agree, and the OH(1720) emission must be
unaccompanied by other OH lines.
