During the operation, four pistols (7.65 mm), magazines and 1 pen pistol were recovered.
Two persons have been arrested who were in possession of the arms and ammunition.
Meanwhile, Chief Minister Himanta Biswa Sarma congratulated Karimganj police for the seizure.
"Kudos to @karimganjpolice for yet another major crackdown. Keep up the good work," he tweeted.