The African Union (AU) has warned Burundi against moves to jeopardise peace efforts after an international arrest warrant was issued for ex-leader Pierre Buyoya and 16 other officials.
They are accused of being behind the 1993 assassination of the country’s first elected Hutu president.
The killing of Melchior Ndadaye triggered a brutal ethnic civil war.
There are fears that targeting Mr Buyoya, an ethnic Tutsi based in Mali, could reignite tensions.
More than 300,000 people died in a 12-year civil war between the minority Tutsi-dominated army and mainly Hutu rebel groups.
Mr Buyoya – who has seized power twice in the last three decades with the backing of the army – is respected diplomatic figure on the continent.
In the past he has reacted angrily to a suggestion that he may have been connected to Mr Ndadaye’s assassination, which took place four months after the country’s first democratic election. He has never issued a formal denial as he had not faced legal charges.
The 69-year-old was involved in the peace process that ended the civil war and saw the election in 2005 of former Hutu rebel leader Pierre Nkurunziza as president.
The current peace negotiations surround the political unrest sparked by Mr Nkurunziza’s decision to run for a third term in office in 2015.
He was ultimately successful, but amid violent opposition protests and a failed coup attempt, hundreds of people died and many of the 400,000 who fled their homes remain in neighbouring countries.
Ahead of a regional summit about the crisis on 27 December 2018, the African Union says that all sides should “refrain from any measures, including political and/or judicial, which may complicate the search for a consensual solution”.