The head of the African Union (A.U.) , President Macky Sall of Senegal, has expressed “grave concern” at rising tensions between the Democratic Republic of Congo and Rwanda.
Each country accuses the other of backing armed rebel groups.
Mr Sall appealed for calm and urged both sides to resolve their dispute through dialogue.
On Saturday Rwanda said two of its soldiers – Élysée Nkundabagenzi and Ntwari Gad – were being held captive in eastern DR Congo by the Rwandan Hutu FDLR militia, which it says gets support from Kinshasa.
Earlier, DR Congo suspended flights to Rwanda and summoned Kigali’s ambassador – accusing its neighbour of backing M23 rebels, who it now officially designates as terrorists.
The M23 have also been excluded from the Nairobi peace negotiations between the Congolese government and numerous militia groups fighting in its eastern region.
“I am seriously concerned by the rising tension between Rwanda and the Democratic Republic of Congo,” Sall said on Twitter.
“I call for calm and dialogue between the two countries, and for the peaceful resolution of the crisis with the support of regional mechanisms and the African Union,” said Sall who holds the rotating chairmanship of the African Union (A.U).
