France says two of its soldiers have been killed in the Central African Republic -- France's first casualties since it sent more troops to the country to help end months of instability.
President Francois Hollande's office said Tuesday the soldiers were killed in overnight clashes in the capital, Bangui.
In an interview on France 2 television, French Defense Minister Jean-Yves Le Drian said the soldiers were caught in an outbreak of violence during an operation to disarm militias that, in his words, "have been spreading terror" in the CAR for several weeks.
Some 1,600 French troops are working with African forces as part of a U.N.-mandated effort to restore security and protect civilians in the CAR.
President Hollande is due to travel to the country later in the day.
Meanwhile, angry Christians set fire to a mosque in Bangui Tuesday.
U.S. President Barack Obama has issued a recorded message to the people of the CAR, urging them to remain calm in the midst of rising sectarian violence that led to at least 400 deaths in two days last week.
He called on them to "choose a different path."
"Respected leaders in your communities, Muslim and Christian, are calling for calm and peace. I call on the transitional government to join these voices and to arrest those who are committing crimes. Individuals who are engaging in violence must be held accountable in accordance with the law."
A Pentagon spokesman said Monday the U.S. would transport African Union peacekeeping troops from neighboring Burundi to the Central African Republic.
U.S. Defense Secretary Chuck Hagel agreed to the move after the French defense minister asked for the airlift assistance.
The instability in the impoverished country began in March, when the rebel Seleka movement ousted President Francois Bozize but then disintegrated.
Witnesses have reported widespread looting and lawlessness, with the interim government unable to restore order.
Recent weeks have seen rising clashes between the mostly Muslim ex-rebels and mostly Christian armed groups known as anti-balaka.