Gunfire and an explosion have been heard near the army headquarters and the French embassy in the capital of Burkina Faso, Ouagadougou.
Witnesses have reported seeing armed men getting out of a car and opening fire before heading towards the embassy.
“An attack is under way,” the French ambassador tweeted.
Pictures from the scene showed a cloud of black smoke rising into the sky. It is unclear who is behind the violence.
The national police have issued a statement saying special forces are in action.
A statement on the French embassy’s Facebook page said it was not clear which locations are being targeted.
It appears to be a twin assault as the city’s military barracks and the embassy are about one kilometre (half a mile) apart.
Ouagadougou has suffered two major attacks by Islamist militants in the last two years.
The West African country also saw a failed coup in 2015. The trial for dozens of the alleged perpetrators began earlier this week but was suspended after defence lawyers walked out in protest against the military court.
By Africafrique and agencies