"During this incident, soldiers from the intervention brigade of the MONUSCO force returning from leave opened fire at the border post for unexplained reasons and forced their way through," the UN mission in Kasindi said in a statement. "This serious incident caused loss of life and serious injuries."
Video of the incident, shared on social media showed men, at least one in police uniform and another in army uniform, advancing towards the immobilized UN convoy behind a closed barrier in Kasindi. The town is in eastern DR Congo's Beni territory on the border with Uganda.
After a verbal exchange, the peacekeepers appeared to open fire before opening the gate, driving on and continuing to shoot while people scattered or hid.
Barthelemy Kambale Siva, the North Kivu governor's representative in Kasindi, earlier said that "eight people, including two policemen who were working at the barrier, were seriously injured" in the incident. At that time, no information on fatalities was provided.
Kambale Siva, interviewed by AFP, did not give a reason for why the UN convoy was prevented from crossing the barrier.
The UN first deployed an observer mission to the region in 1999.
In 2010, it became the peacekeeping mission MONUSCO -- the United Nations Organization Stabilization Mission in the Democratic Republic of the Congo -- with a mandate to conduct offensive operations.
There have been 230 fatalities among them, according to the UN.
Last week, deadly demonstrations demanding the departure of the United Nations took place in several towns in eastern DRC.
A total of 19 people, including three peacekeepers, were killed.
Anger has been fuelled by perceptions that MONUSCO is failing to do enough to stop attacks by the armed groups.
UN under-secretary-general for peace operations Jean-Pierre Lacroix was in the central African country on Saturday to "talk to the Congolese authorities", he said.
"(They would) examine ways in which we can both avoid a recurrence of these tragic incidents and, above all, work better together to achieve our objectives," he said.
"We hope that the conditions will be met, in particular the return of state authority, so that MONUSCO can complete its mission as soon as possible. And to leave room for other forms of international support."