5972
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 .
 Guerrero, ERP
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, else, organization, person 
Text: {0} 
Answer:
 Guerrero, ERP