Security forces in Madagascar used tear gas to break up opposition marchers in the capital, Antananarivo, on Wednesday.
The protesters were marching to the presidential palace to deliver a letter to military-backed leader Andry Rajoelina. The letter asked Mr. Rajoelina if he still supports reconciliation as a way to end the country's political turmoil.
Political tension in Madagascar has been rising as Mr. Rajoelina and opposition groups move separately to form new governments.
Mr. Rajoelina pulled out of a power-sharing agreement in December and named a new prime minister, Colonel Albert Camille Vital. Opposition groups charged the action was illegal and began to create their own government.
African Union commission chief Jean Ping has called for the sides to resume power-sharing talks.
Ping spoke Wednesday as he and mediators in the Madagascar talks met at AU headquarters in Ethiopia.
Madagascar has been mired in political crisis since March, when Mr. Rajoelina seized power with the help of the military.
Ousted President Marc Ravalomanana leads one of the three opposition factions seeking to form a unity government.
International mediators have brokered several power-sharing agreements during talks in Mozambique, but none of the deals has been implemented.
Some information for this report was provided by AFP, AP and Reuters.