A source told AFP "An outlying gendarmerie post in Seytenga in Seno province was targeted by terrorists last night."
Another security source confirmed the attack, the latest in a string of bloody assaults in the landlocked Sahel state.
Friday's bloodshed followed an attack at the Karma industrial gold mine in northern Burkina Faso in the early hours of Thursday morning, killing one soldier and one mine employee, the company said.
The company said the assailants were not identified, and that the attack was eventually repelled by mine security workers and soldiers. It is still evaluating the impact, it said.
Islamist militants linked to al Qaeda and Islamic State have been waging an insurgency in northern Burkina Faso for nearly a decade and routinely carry out attacks.
Several of those have targeted convoys on their way to and from the region's gold mines. An ambush on buses carrying employees of Canadian firm Semafo in 2019 was the deadliest, killing 39 people.
The president of Burkina Faso's mines chamber said in April that extra measures would be taken to protect gold projects in the north after Russia's Nordgold shut down its mine there, citing deteriorating security.
Also on Thursday, four gendarmes were killed in an attack at Barani, in the northwest.
One of the poorest countries in the world, Burkina Faso has been gripped by a nearly seven-year-old insurgency launched by jihadists crossing from neighboring Mali.
More than 2,000 people have died and some 1.8 million people have fled their homes.
Attacks have been concentrated in the north and east of the country.
The nation has been under military rule since January, when colonels angered at failures to roll back the insurgency ousted the elected president, Roch Marc Christian Kabore.
