bogota peace deal colombia marxist farc rebel threaten drug traffic cultivation coca base ingredient cocaine peace official say thursday wake confrontation coca farmers police kill seven drug traffic illegal crop important threats rodrigo rivera country peace commissioner tell reuters office inside presidential palace element exist like honey attract be circle create new organize crime territories farc long rivera say government president juan manuel santos revolutionary arm force colombia farc rebel sign peace accord last year end roles conflict kill least 220,000 people thousands farc fighters demobilize deal group political party crop substitution already thorn side government last week least seven farmers protest eradication kill confuse incident police tumaco southwestern colombia defense ministry accuse dissident former farc members stoke confrontation fire crowd farmer group accuse jittery police shoot disperse protest investigation incident ongoing well dissidents rebel group crime gang begin take coca areas security source say gang often offer ex-combatants high salaries entitle peace deal dissidents gang siren call ex-rebels rivera say subsistence farmers often oblige rebel group paramilitaries crime gang plant coca also choose grow crop illegal group pay high price farmers earn products tempt possibility amid dire poverty coca cultivation reach level see decade last year government ban aerial fumigation glyphosate herbicide link cancer prohibition spark criticism unite state set give andean country 400 million fund help farc deal coca cultivate 188,000 hectares 464,000 acres across colombia cocaine production capacity 700 tonnes annually government want eradicate 100,000 hectares year coca traffic great threats colombia peace official