yaounde militants seek independence cameroon english-speaking regions kill four gendarmes monday government say dispute francophone-dominated government degenerate open warfare several separatists kill security force ensue clash government spokesman say repression president paul biya government begin peaceful protest year ago anglophone activists perceive social economic marginalization bolster support arm militants demand full break yaounde separatists launch series deadly raid government police soldier recent weeks lead authorities escalate crackdown kill dozens civilians issa tchiroma bakary cameroon government spokesman say separatists kill four gendarmes early monday town kembong southwest region manyu division assailants ensnare measure put place defense security force reduce sporadic attack carry hide face use perfidy tchiroma say representative separatists could immediately reach comment manyu dense equatorial forest along nigerian border become center insurgency separatists launch series attack security force villages violence fuel mount refugee crisis least 7,500 people cross nigeria since oct. secessionists declare independent state call ambazonia u.n. refugee agency say brace many 40,000. cameroon linguistic divide hark back end world war one german colony kamerun carve ally french british victors english-speaking regions join french-speaking republic cameroon year independence 1960. french speakers dominate country politics since tensions long simmer recent violence serious date emerge serious challenge biya 35-year rule 84-year-old expect seek new term election next year cameroon separatists kill four gendarmes anglophone crisis worsen