Security forces battled suspected Islamist fighters who were holding hostages at hotel used by foreigners in Burkina Faso's capital on Friday, gendarmes and witnesses said.
The gunmen stormed the Splendid Hotel in Ouagadougou's business district, burning cars outside and firing in the air to drive back crowds before security forces arrived, prompting an intense exchange of gunfire.
The hotel is sometimes used by French troops with Operation Barkhane, a force based in Chad and set up to combat Islamist militants across Africa's vast, arid Sahel region.
"It is continuing at this time. We are trying to know how many attackers they are to better coordinate our actions. Hostages have been taken. The operation could take several hours," a senior official with the national gendarmes said, asking not to be named.
A Reuters witness saw gunmen emerge from the hotel and fire into the air. A vehicle carrying security personnel arrived and shortly afterwards an intense gun battle began.
The landlocked West African state has endured bouts of political turmoil since Oct. 2014 when veteran President Blaise Compaore was overthrown during mass protests.
But it has been largely spared violence by Islamist militants who have staged attacks in Mali, a country with which it shares a 600-km (375-mile) border.
The attack would be the first in Burkina's capital by Islamists in a country that is diverse in religious terms and has a population that is around 60 percent Muslim, according to government figures.
It would present a significant challenge to President Roch Marc Kabore, who was elected in Nov. 2015 as Burkina Faso's first new leader in decades.
The French embassy in December warned its citizens against traveling to a national park in eastern Burkina Faso after reports that Malian jihadists were threatening to kidnap foreigners.
An Islamist militant group Al-Mourabitoun said in May, 2015, it was holding a Romanian man kidnapped from a mine in northern Burkina Faso the previous month.
Around 50 unidentified gunmen attacked a Burkina Faso gendarmerie brigade near the country's western border with Mali in Oct. 2015, killing three in an attack the then government blamed on the leaders of a failed coup one month before.
Islamist militants have staged attacks in a number of West African states bordering the Sahel in recent years.
Two militants killed 20 people from nations including Russia, China and the United States at a luxury hotel in Mali's capital on Nov. 20, 2015, before being killed by the security forces.
Three Islamist groups including al Qaeda in the Islamic Maghreb claimed responsibility for that attack, the most prominent by militants who are based in the north of the country and have staged a series of attacks over the last year.
Boko Haram have killed thousands in northeastern Nigeria during a six year insurgency and in 2015 extended its attacks into neighboring countries Chad, Niger and Cameroon.
(Additional reporting by Brice Makini in Dakar and Joe Bavier in Abidjan; Writing by Matthew Mpoke Bigg; Editing by Andrew Heavens)