There is a serious risk that if violence in Burundi isn't stopped there could be a civil war " and after that, " everything is possible," the U.N. special adviser on the prevention of genocide said Tuesday ,AP reported. Adama Dieng told reporters he is using the occasion of the first international day to commemorate victims of genocide on Wednesday to call on Burundi's government and opposition to end the violence and negotiate a political solution to restore peace to the troubled African nation. Dieng says he is also calling on Burundi's neighbors, including Rwanda and Tanzania, which has seen a large influx of Burundians fleeing the violence, to help. President Pierre Nkurunziza's decision to seek a third term, which he won in a disputed election, has triggered months of violence, including an abortive coup attempt. At least 240 people have been killed since April and about 215,000 others have fled to neighboring countries, according to the U.N.