Suspected Ebola cases in eastern Congo have topped 900, Congolese authorities said Sunday, as the response to an outbreak already declared a global health emergency is being undermined by armed conflict, mass displacement, and a steep drop in international aid. The Congolese Ministry of Communication said there were 904 suspected cases, mainly in Ituri Province, and 119 deaths — though its own regional data added up to 220. Officials could not immediately be reached to explain the discrepancy.

Late Sunday, armed young men stormed a hospital treating Ebola patients in the town of Mongbwalu. “The attackers demanded that two bodies of their kin be handed over to them,” Dr. Richard Lokudu, the hospital’s director, said. Medical staff evacuated patients as gunfire rang out; it was not immediately known if anyone was hurt. The attack followed the arson of two health centers last week at the heart of the outbreak. Physicians for Human Rights described what is unfolding as “a devastating set of emergencies converging.”

The region has been plagued for years by dozens of rebel and militant groups, including the Rwanda-backed M23 rebels and the Allied Democratic Forces, a Ugandan Islamist group linked to the Islamic State, which is active in Ituri. The United Nations says nearly a million people have been displaced by the violence in the province. “This Ebola outbreak is unfolding in communities already facing insecurity, displacement and fragile health care systems,” said Gabriela Arenas, a regional coordinator at the International Federation of Red Cross and Red Crescent Societies. Humanitarian officials worry the disease could spread to large displacement camps near the city of Bunia, where the first cases were detected.

Last year’s aid cuts by the United States and other wealthy nations were especially damaging in eastern Congo, health experts said. “The cuts reduced the capacity to detect and respond to infectious disease outbreaks,” said Thomas McHale, public health director at Physicians for Human Rights. Congo has experienced more than a dozen previous Ebola outbreaks, but the Bundibugyo strain driving the current one has no approved vaccine or treatment. Aid groups on the ground report critical shortages. “We have made requests to different partners but we have not yet really received anything,” said Julienne Lusenge, president of Women’s Solidarity for Inclusive Peace and Development, which runs a small hospital near Bunia. “We only have hand sanitizer and a few masks for the nurses.”

Anger in local communities has also been stoked by the strict burial protocols imposed to limit contagion. The government has banned funeral wakes and gatherings of more than 50 people, and soldiers and police are guarding some burials conducted by aid workers. Colin Thomas-Jensen, director of impact at the Aurora Humanitarian Initiative, said the attacks on health facilities may reflect “built-in skepticism and anger” over the failure of both the Congolese government and international peacekeepers to protect the population from years of violence by foreign-linked armed groups.

The outbreak has