Rwanda’s army said the around 100 attackers arrived from Burundi, but Burundi has denied the accusation.
Rwanda’s army said the attackers had an “intention to kill civilians” in Yanze village and withdrew after clashing with Rwandan soldiers.
Four of the attackers were killed and three others captured, while three Rwandan soldiers were injured, it said.
Burundi’s army responded by saying its territory “can’t be a sanctuary for armed elements to destabilise neighbouring countries”.
The two east African neighbours have unsolved political tensions since a coup against the late President Pierre Nkurunziza aborted in April 2015. He accused Rwanda of having a hand in the coup, but Rwanda denied any involvement.
The five years of tension have hampered trade and cross-border activities between the two countries.
Burundi has a new president who took office last week. Some expect him to normalise relations with the country’s northern neighbour.