text: Leftist Mexican armed group says troops in capital . MEXICO CITY 1996-08-25 The leftist Popular Revolutionary Army ( EPR ) in a published report on Sunday said it operated throughout Mexico , including the capital , and denied government assertions it was isolated to one state . Commanders " Vicente " and " Oscar " , guarded by a dozen EPR gunmen , said in an interview with La Jornada outside Mexico City that the armed group was committed to overthrowing the government . " They ( government officials ) want to present us before public opinion as a local problem , as just being from Guerrero and as irrational radicals , " Commander Oscar told La Jornada . They said the ERP , whose fighters first appeared wearing military fatigues and brandishing assault rifles in the southwestern state of Guerrero on June 28 , had a 23,000-strong membership , but this could not be confirmed independently . La Jornada also reported on Sunday that the Mexican Army has discovered a 37-page , EPR manual detailing guerrilla tactics and strategies . It quoted the manual as saying : " The objective of the Basic Course on War is to provide for combatants of the EPR basic military knowledge for the armed conflict against the police and military apparatus of the bourgeoisie . " It was the second time armed " commanders " of the EPR have granted interviews outside Guerrero state , an extremely poor and volatile region where leftist protesters often have clashed violently with authorities . Unlike the better known and unrelated Zapatista rebels in southeastern Chiapas state , the EPR has never taken on the army in direct combat , according to official reports . There have only been a few skirmishes in Guerrero in which a handful of police , soldiers and civilians have been killed or injured .