“A military vehicle hit a homemade explosive planted by suspected terrorists,” on the road between Fada and Pama, a source said.
“A lieutenant and two enlisted men died,” the source said, adding that four other soldiers were injured and were taken to hospital.
Burkina Faso has been battling jihadist attacks over the last three years, beginning in the north of the country but now spreading to the east, near the border with Togo and Benin. Its other neighbours are Mali and Niger.
Since the jihadist violence began in March 2015, more than 200 people have been killed, official figures show.