Military coups have been a regular occurrence in Africa in the decades since independence and there is now concern they are becoming more frequent.

Sudan has this year experienced two such events, one in September which failed and the latest in which Gen Abdel Fattah Burhan dissolved the civilian arm of a transitional government and took over.

In Guinea, President Condé was ousted by the army in September and in neighbouring Mali there have been two interventions by the army in less than a year, the most recent one in May.

In Niger, a coup was thwarted in March just days before a presidential inauguration.

So are military interventions occurring more often on the continent?

A coup is under way in Sudan, where the military has dissolved civilian rule, arrested political leaders and declared a state of emergency.

The coup leader Gen Abdel Fattah Burhan has blamed political infighting.

Protesters have taken to the streets of the capital, Khartoum, and other cities and there are reports of gunfire.

Military and civilian leaders have been at odds since long-time ruler Omar al-Bashir was overthrown two years ago and a transitional government set up.

Army and paramilitary troops have been deployed across the capital, Khartoum airport is closed, and international flights are suspended. The internet is also down.

BBC Arabic's Mohamed Osman, in Khartoum, says large numbers of protestors are demanding the return of civilian rule and that demonstrations have spread to a number of other locations, including the cities of Atbara, Wad Madani and Port Sudan.

More protestors are expected to be drawn to the streets in the coming hours after calls for action by political parties and professional unions, our correspondent adds.