Security forces in Madagascar have fired tear gas against opposition candidates who were leading a protest in the capital, Antananarivo.

It comes amid rising tensions ahead of presidential elections next month.

Eleven of the 13 presidential candidates had urged their supporters to march towards the city’s central square, to protest against what they described as an institutional coup in favour of the incumbent Andry Rajoelina.

But reporters from the AFP news agency said the security forces dispersed the crowd before it reached its destination.