Health officials have warned that the second-deadliest outbreak of Ebola may spiral out of control unless attacks by armed groups on medical facilities and workers in the Democratic Republic of Congo (DRC) stop.

Speaking to reporters in Geneva on Wednesday, DRC's health minister Oly Ilunga Kalenga, said the government of his country was struggling to contain the spread of the virus, amid a spike in violent attacks against doctors and hospitals that were dangerously delaying the emergency response.

Kalenga said the real emergency they face right now is security, on the sidelines of the World Health Assembly which is under way this week in the Swiss city.

He said each time there is an attack on a health facility or medical personnel, the response to the epidemic is put on hold, and they lose precious time to stop the virus from spreading further.