The African Union will send a 5,000 strong force to stop violence in troubled Burundi, giving Bujumbura a four-day deadline to agree but warning it would send troops anyway. The move comes as international alarm grows over spiraling violence in the tiny, landlocked nation which has been mired in bloodshed since April, sparking concern it was sliding toward civil war. The AU force "shall have an initial strength of up to 5,000 military personnel and police," the AU's Peace and Security Council (PSC) said in a statement late Friday. Burundi has so far dismissed proposals for any peacekeeping force, but the AU said if it refuses to accept the troops, the bloc would "take additional measures" to ensure its deployment. And it underlined its "determination to take all appropriate measures against any party or actor... who would impede the implementation of the present decision." Burundi descended into bloodshed in April when President Pierre Nkurunziza announced his intention to run for a controversial third term, which he went on to win in July. Nkurunziza is an ex-rebel and born-again Christian who believes he has divine backing to rule. The force is mandated to "prevent any deterioration of the security situation" as well as to protect civilians and "contribute to the creation of the necessary conditions for the successful holding of the inter-Burundian dialogue." Talks between the government and opposition have repeatedly collapsed. No details were given as to which countries might send troops — or when they would be deployed. The new force, dubbed MAPROBU — the French acronym for the African Prevention and Protection Mission in Burundi — will have an initial renewable mandate of six months. The bloc urged talks among its members, including those in its regional East African Standby Force (EASF), "to generate the troops and police elements needed to quickly reach the authorised strength." The 10-nation EASF includes Burundi itself, and is one of five AU regional bodies with a mandate to boost "peace and security." It has never deployed and is currently a force in principle only, with the AU calling on the UN Security Council "to support the deployment." Earlier this week UN Secretary General Ban Ki-moon said he was dispatching an envoy for urgent talks to end the crisis, warning that Burundi was "on the brink of a civil war that risks engulfing the entire region." Ban has also raised the option of deploying UN peacekeepers to quell the violence but recommended that a UN team be first sent to bolster dialogue. The upsurge in violence has raised fears of a return to civil war, a decade after the end of a 1993-2006 conflict between rebels from the Hutu majority and an army dominated by minority Tutsis, which left 300,000 people dead. The violence escalated dramatically last week with the killing of 87 people in clashes in Bujumbura, many of them youths shot dead by the security forces. AU rights investigators this week returned from a fact-finding mission to Burundi expressing "great concern" after witnessing some of the heaviest fighting in the troubled country for months. The AU team said they had reports of "arbitrary killings and targeted assassinations" as well as arrests, detentions and torture. Their concerns have been widely echoed.