UN Secretary-General Ban Ki-moon voiced outrage after Burkina Faso's presidential guard detained the country's interim president and prime minister, and demanded their immediate release.
The crisis in Burkina Faso deepened after the opposition stormed out of talks on a transition government at the inclusion of supporters of deposed president Blaise Compaore.
The first ladies of Ivory Coast and Burkina Faso on Thursday sealed an agreement to fight the growing child trafficking trade between the two west African nations.
For the many Malians who have fled to Burkina Faso in recent days, facing life in a refugee camp won out over the horrors of war, after already suffering through occupation by hardline Islamist rebels.
A coalition of Malian political parties and a citizen's association based in the Islamist-occupied north on Sunday objected to Algeria and Burkina Faso's role in mediating their country's crisis.
Burkina Faso led efforts Sunday to persuade one of the armed Islamist groups controlling northern Mali to cut ties with Al-Qaeda as a west African military intervention looms to end the crisis.