nairobi burundi main opposition group say boycott peace talk resume tuesday tanzania leave little chance negotiations end simmer political violence claim hundreds live burundi grip unrest since april 2015 president pierre nkurunziza announce would stand third term opposition say violate constitution well 2005 peace deal end civil war vote largely boycott opposition protest spark government crackdown kill 700 people displace 400,000 neighbor countries leave economy moribund international criminal court investigate whether pro-government force commit war crimes include murder torture rape burundi withdraw court refuse recognize investigation exile opposition group cnared say former tanzanian president benjamin mkapa facilitate nov. 28-dec. round talk arusha invite always ask facilitator invite cnared opposition bloc refuse rather decide select members take part dialogue without consent say cnared spokesman pancrace cimpaye end october burundi cabinet adopt draft legislation seek change current constitution allow nkurunziza run fourth term 2020 election propose amendments likely go referendum next year seek abolish two-term limit lengthen presidential term seven years cnared say amend constitution worsen crisis burundi opposition platform boycott new round peace talk tanzania