The latest outbreak of Ebola in Democratic Republic of Congo is still a long way from being brought under control, a senior World Health Organization official has said.

In an interview with the Telegraph, Peter Salama, WHO's deputy director-general for emergency preparedness and response, said that in the original epicentres of the disease – around the towns of Mangina and Beni in the north east of the country – there were "promising signs" that the disease was coming under control.

But in the city of Butembo – where there have been four cases – the situation was less certain.

“Until we have traced every contact we cannot say for certain that the disease is under control,” he said.

The latest figures from WHO show that there have been 133 cases of the disease, including 91 deaths – making it the eighth largest Ebola outbreak in history.

The outbreak has been ongoing since the beginning of August in the north east of the country, where a number of militant groups operate and security is poor.