The man was herding his cow using a porous entry point, according to the Executive Secretary of Rubavu district, Olivier Ruhamyambuga.
The 36-years-old Congolese man who was identified as Jean Pierre Simbizi Niyobuhungiro was returning to DR Congo from Rwanda before being intercepted by a military patrol on the Rwandan side of the border.
The incident took place in Rukoko village neara porous border point in , northwestern Rwanda, Ruhamyambuga said, adding that the man was shot along with his cattle.
In March this year, three young smugglers of used clothes were shot dead after the Rwandan army spotted a group of people approaching the border at Cyanzarwe sector of Rubavu district in the northwest of the country.
The Rwandan army has stepped up its patrol of the border with DR Congo to prevent Hutus mitilias operating mainly in the east of that country from crossing into Rwanda.
Currently about 7,000 people cross the Rwanda-DR Congo border each day through the area commonly called Grande Barriere on the Rubavu-Goma border.
45,000 people cross another Rubavu-Goma border post called Petite Barriere.
In a recent report, the United Nations has expressed worries over the continued existence of the Democratic Forces for the Liberation of Rwanda (FDLR), rebels linked to the 1994 genocide, in eastern DR Congo.