The head of the World Health Organization (WHO) on Wednesday called for a ceasefire in eastern Democratic Republic of Congo (DRC) in order to contain an Ebola outbreak, saying that ongoing fighting was driving mass displacement and spreading the disease in overcrowded camps.

The Bundibugyo strain of Ebola, for which there is no approved vaccine or treatment, was declared an emergency of international concern by the World Health Organization earlier this month and cases are rising sharply.

"Eastern DRC now faces a catastrophic collision of disease and conflict with the Ebola outbreak in Ituri province outpacing the response," said WHO Director-General Tedros Adhanom ​Ghebreyesus, who is due to travel to the region this week.

"We cannot build community trust or isolate the sick while bombs are falling. We urge all warring parties to agree to an immediate ceasefire to contain this outbreak," he said on X.

Over 900 suspected cases and over 200 suspected deaths have so far been reported in three provinces in eastern Congo including the North Kivu province, held by Rwanda-backed M23 rebels, and South Kivu province, controlled by rebel group the Alliance Fleuve Congo.

Aid group Save the Children said on Wednesday a quarter of the confirmed deaths were children, calling for a scale-up in infection prevention measures.

Fighting has continued in eastern Congo despite mediation efforts led by the United States and others, and millions of people are displaced. The UN refugee agency said transit and reception sites in Uganda's West Nile region which borders Congo are at more than double capacity, a document showed.

Aid groups are rushing staff and equipment to eastern Congo but attacks on medics due to community distrust have hampered efforts, they say. So far, donors have pledged around $500-million to help with the outbreak but not all has been disbursed, according to health officials.