Kigali - Growing violence in Burundi is a danger to the entire region and the international community must act to keep the crisis from escalating, the UN's Special Representative for Central Africa said on Thursday.Burundi has been in chaos since late April when President Pierre Nkurunziza announced he would seek a third term in office, a move his opponents and Western powers said violated a peace deal that ended an ethnically-charged civil war in 2005.Nkurunziza was declared the winner of the July 21 election.But tensions have remained high, especially in the capital Bujumbura, where the sound of gunfire is regularly heard at night."This escalation of violence is a danger for the whole region and so something has to be done," Special Representative Abdoulaye Bathily said after an hour-long meeting with Rwandan President Paul Kagame, whose country borders Burundi and has a similar ethnic make-up."After almost 20 years of violence, civil war, it would be really sad for Burundi to plunge again into a new circle of violence," he said. "The time is for peace. The time is not for senseless killing, retaliation, reprisal," he said.In a region still scarred by the 1994 Rwandan genocide, when 800 000 Tutsi and moderate Hutus were slaughtered, leaders fear the violence could split the country down ethnic lines and lead to another civil war.More than 140 000 refugees have fled Burundi since March, as security forces began a violent crackdown on protests.There have also been fears of reprisal killings, and forces loyal to Nkurunziza looking to punish those who opposed his bid and backed a thwarted coup.On Monday, human rights activist Pierre Claver Mbonimpa, who openly opposed Nkurunziza's controversial bid for a third term, was shot and seriously injured, just a day after Nkurunziza's former security chief General Adolphe Nshimirimana was ambushed and killed.Officials and a Mbonimpa family member said on Thursday that Mbonimpa has been given approval to travel abroad for medical treatment.Mbonimpa's daughter Zygene Mbonimpa said the activist, who heads the Association for the Protection of Human Rights and Detained Persons (APRODH), would likely go to Kenya or Belgium.Human Rights Watch issued a statement on Thursday saying it had documented 148 cases between April and July of suspected government critics being arbitrarily arrested and then "beaten, tortured, or otherwise ill-treated."