What is Ebola and why is stopping this outbreak so difficult?

He said public health information campaigns were "providing information on how to handle funerals" and the importance of basic hygiene and sanitation, as well as providing protection measures for health workers.

Kamba said the outbreak was slow in being reported due to infected communities believing it to be "witchcraft" or a "mystical illness", resulting in people seeking treatment from prayer centres and witchdoctors rather than hospitals.

The first reported cases were in the Ituri towns of Mongwalu and Rwampara, as well as Bunia.

There has also been a case in eastern DR Congo's biggest city, Goma, which has a population of around 850,000 people and is under rebel control.

In Goma, the confirmed case involved a woman who had travelled to the city after her husband died of Ebola in Bunia, Jean-Jacques Muyembe, the director of the Congolese Institut National de Recherche Biomédicale (INRB), told AFP news agency.

One person has also died in Uganda's capital, Kampala, while another is being treated. They were both Congolese nationals who had recently travelled to the country.

The government has sent health teams to Bunia with protective equipment.

The WHO and medical charity Médecins Sans Frontières (MSF) are also present. They are setting up treatment centres and working on a response plan.

A toll-free number, 151, has been provided for reporting symptoms.

Residents have been urged to take measures such as:

• calling immediately when symptoms appear
• avoiding contact with bodies of people who died with symptoms, or with dead animals
• not eating raw meat, as undercooked food may transmit the virus
• practising social distancing

Goma, the capital of the North Kivu province, is currently controlled by rebels from the AFC-M23 group, who say they are creating an Ebola response team.

On Sunday, AFC-M23 spokesman Lawrence Kanyuka said they had "immediately activated" response mechanisms in conjunction with health services and local medical facilities, to prevent the spread of Ebola in areas under their control.

Neither the government nor the rebels have said whether they would be willing to put aside their differences to work together to tackle the outbreak.

However, the case in Goma was confirmed by the INRB, which is a state-run body, so that does provide some grounds for optimism.

Africa CDC has warned of the high risk of spread to countries that border DR Congo, specifically Uganda, Rwanda and South Sudan.

It expects to speak to the four countries on "how to strengthen the response".

Rwandan authorities have said they are reinforcing their screening for people entering the country after the confirmed case in Goma, which is on its border.

One Congolese man told the BBC that he had been blocked from crossing from Goma into Rwanda.

But he said that he was told that Rwandans were being allowed to go back home, and so were Congolese nationals living in Rwanda.

In Uganda, President Yoweri Museveni has postponed the Martyrs' Day pilgrimage, a Christian holiday held on 3 June each year, which usually draws thousands of Congolese nationals to join festivities.