The BBC has announced that its Africa editor, Fergal Keane, is stepping down from his role.

The Irish man is to leave his post due to post-traumatic stress disorder (PTSD), the British broadcaster said.

The corporation's head of newsgathering, Jonathan Munro, said his diagnosis was the result of "several decades of work in conflict zones around the world".

He added that Mr Keane had "been dealing privately with the effects of PTSD for several years".

He will continue to report for BBC News, but in a new role.

In a memo to staff, Mr Munro said the reporter had been supported "by friends and colleagues in news, as well as receiving professional medical advice" after his diagnosis.

"However, he now feels he needs to change his role in order to further assist his recovery.

"It's both brave and welcome that he is ready to be open about PTSD".

Fergal Keane joined the BBC in 1989 as its Northern Ireland correspondent, and later covered South Africa and Asia - before being appointed Africa editor.

He won an Amnesty television prize in 1994 for his investigation of the Rwandan genocide.