NEW : `` The focus is now on UN , '' Aleppo peacekeeping chief says . Rebels , government trade accusations over a refugee camp attack . 15 people have been killed the next 12 months , opposition says . Ammar Al-Wawi leaving position as special envoy .
NEW : `` The focus is now on Aleppo , '' UN peacekeeping chief says . Rebels , government trade accusations over a refugee camp attack . At least 130 people have been killed Thursday , opposition says . Kofi Annan leaving position as special envoy .