KIGALI, Rwanda (AP) — Rwanda’s army said its troops briefly exchanged fire with soldiers from Congo early Wednesday, in a new spike in tension between the neighbors who have accused each other of supporting armed rebel groups on the other side of the border. Congo denied that account.

A statement said that twelve to fourteen Congolese soldiers entered the no man’s land near the western district of Rusizi and opened fire at a Rwandan border post, in “an act of provocation.”

“Our security forces responded and (the Congolese) soldiers withdrew,” the Rwandan statement said. “There were no casualties on the Rwanda side and the situation is calm.”

Congo’s government said there were clashes between its military and a group of “bandits” near the border in Bukavu, but denied entering the neutral zone.

“In no case did the (army) cross the neutral zone, let alone open fire in the direction of Rwanda,” Theo Ngwabidje Kasi, governor of South Kivu province, said in a statement.

Congo for months has accused Rwanda of supporting an armed rebel group called M23, that’s fighting in eastern Congo.

The conflict in eastern Congo has gone on for decades, with more than 100 armed groups fighting for control of valuable mineral resources while others protect their communities, and has triggered an exodus of refugees.

Rwanda in turn accuses Congo of supporting the FDLR, a Rwandan armed rebel group based in Congo that has carried out raids into Rwanda in the past. The FDLR has been accused of participation in the 1994 Rwandan genocide, in which ethnic Hutus killed more than 800,000 ethnic Tutsis and moderate Hutus who tried to protect them.

United Nations experts in December said they had “substantial evidence” of Rwandan government forces crossing into Congo to reinforce M23 rebels or to conduct operations against the FDLR. The United States, France and Germany have urged Rwanda to stop supporting the rebels.

The Rwandan government has denied supporting M23 and says the accusations are part of a “tired old blame game” undermining efforts for peace, “to which Rwanda is fully committed.”

Rwanda’s President Paul Kagame has said Congolese authorities should solve their own problems. In January he said that the crisis in Congo “is not Rwanda’s problem, and we are going to make sure that everybody realizes it is not Rwanda’s problem.”

Last month, Rwanda said it fired on Congo military aircraft it accused of violating its airspace and urged Congo to stop the “aggression.”

But Congo’s government said the incident occurred in Congolese airspace near the city of Goma’s international airport. It said the plane landed without major damage.

Congo had described the attack on its aircraft as “a deliberate act of aggression that equals an act of war” with the goal of sabotaging regional peace efforts.

Regional leaders called for a cease-fire in eastern Congo and ordered a withdrawal of rebels from major towns under M23 control — which hasn’t happened.

Copyright © The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.