The capital of Burkina Faso came under multiple attacks on Friday, targeting the French embassy, the French cultural centre and the country's military headquarters.
Witnesses said five armed men got out of a car and opened fire on passers-by before heading towards the embassy, in the centre of the city. There were heavy exchanges of gunfire and police and army units were deployed in the area.
There was also an explosion near the headquarters of the Burkinabe armed forces and the French cultural centre, which are located about a kilometre from the site of the first attack, witnesses said.
The French embassy confirmed that French interests were under attack.
"Attack under way at the French embassy and French Institute. Stay indoors," it said in a message posted on Facebook.
Burkina Faso is one of a string of fragile countries on the southern rim of the Sahara that are battling extremist groups.
The insurgency has caused thousands of deaths, prompted tens of thousands to flee their homes and dealt crippling blows to economies that are already among the poorest in the world.
On August 13 last year, two assailants opened fire on a restaurant on Ouagadougou's main avenue, killing 19 people and wounded 21. The attack remains unclaimed.
On January 15 2016, 30 people, including six Canadians and five Europeans, were killed in an attack on a hotel and restaurant in the city centre.
Responsibility was claimed by a group called Al Qaeda in the Islamic Maghreb.
France, the former colonial power in the Sahel region, has deployed 4,000 troops and is supporting a five-country joint force gathering Burkina Faso, Chad, Mali, Mauritania and Niger.
The United Nations also has a 12,000-strong peacekeeping force in Mali called Minusma, which has taken heavy casualties. Four UN peacekeepers were killed by a mine blast on Wednesday in the centre of the country.
In a separate development on Friday, the specialist US website SITE, which monitors terrorist activity, said kidnappers had released a video of a 75-year-old French hostage, Sophie Petronin, who was abducted in northern Mali in late 2016.
Ms Petronin, who had been running an association helping Malian orphans, appears in poor health in the brief video.
Her kidnapping, hitherto unclaimed, was carried out by the "Support Group for Islam and Muslims". In the background, the voice of French President Emmanuel Macron is heard on a loop, saying: "I will protect you."