Rwandan authorities accused Burundi’s leader of making “incendiary allegations aimed at inciting division among Rwandans,” raising tensions that persist after Burundi closed all border crossings with Rwanda earlier this month.

Relations between Rwanda and Burundi have deteriorated in recent weeks after Burundian President Evariste Ndayishimiye renewed accusations that Rwanda is funding and training the rebels of the RED-Tabara group.

Burundian authorities consider RED-Tabara a terrorist movement and accuse its members of being part of a failed coup attempt in 2015. The group first appeared in 2011 and has been accused of a string of attacks in Burundi since 2015.

Ndayishimiye spoke of Rwandan youth in “captivity” at an event in the Congolese capital Kinshasa on Sunday, saying the region needs to continue to fight until Rwandan people put pressure on their own government.

He was addressing a youth conference after attending the inauguration of Congolese President Felix Tshisekedi. He apparently spoke in his other capacity as the African Union Champion for Youth, Peace and Security.

In a statement late Monday, Rwandan authorities described Ndayishimiye’s remarks as “inflammatory,” saying calls for an uprising against the government undermine unity in Rwanda and threaten regional security.

“For anyone to try and undermine this progress by calling on young Rwandans to overthrow their government is troubling. But for a leader of a neighboring country to do so, from an African Union platform, is deeply irresponsible and a flagrant violation of the African Union Charter,” the statement said.

Earlier this month Burundi closed all border crossings with Rwanda and started deporting Rwandan citizens, asserting that it was responding to Rwanda’s alleged support for RED-Tabara. Those rebels attacked the Burundian village of Gatumba near the Congo border last month, killing at least 20 people.

RED-Tabara, which is based in the South Kivu province of eastern Congo, took responsibility for the attack in a post on X, formerly known as Twitter.

“As long as they have a country that provides them with uniforms, feeds them, protects them, shelters them, maintains them, we will have problems,” Ndayishimiye said in a national radio broadcast last month, referring to RED-Tabara.

Rwanda has repeatedly denied the allegations.

Rwanda and Burundi are both members of the East African Community bloc, whose trade ambitions have suffered in recent years amid sporadic flare-ups that undermine the free movement of people and goods.

Congolese authorities also cite Rwandan aggression in eastern Congo, where government troops are fighting to dislodge the violent M23 rebels who control some territory there. Rwanda denies having authority over M23.