On September NUMBER@1 , NUMBER@2 , together with a number of leftist social revolutionaries , the Underground Anarchists bombed the headquarters of the ORGANIZATION@1 of the ORGANIZATION@2 during a plenary meeting .

On September NUMBER@1 , NUMBER@2 , a little group of social revolutionaries and anarchists bombed the headquarters of the `` ORGANIZATION@1 '' of the ORGANIZATION@2 in protest at the growing repression .
