"Arrests have been made in the past few days. France has had no news from several of its compatriots," Jean-Marc Ayrault said in a statement.
"It expresses deep concern in this regard and demands that it be allowed to exercise consular protection under the Vienna Convention," he added.
Ayrault welcomed the decision by the African Union to help the rival parties resolve their electoral dispute and promised France's full support to this initiative. France has maintained significant presence in the country after it became independent in 1960.