SRL for [staged]: In East Berlin , Communist Party officials considered legalizing New Forum , the country 's largest opposition alliance , as about 20,000 demonstrators [staged] protests in three cities to press demands for democratic freedoms .
ARG-0: about 20,000 demonstrators | ARG-1: protests | ARG-M-LOC: in three cities | ARG-M-PNC: to press demands for democratic freedoms