The Africa Centres for Disease Control and Prevention (Africa CDC) reported 87 deaths as of Saturday, up from 65 a day earlier, with 336 suspected and 13 confirmed cases in the outbreak first announced on Friday. Four of the confirmed patients have died. The disease has now spread to the Mongwalu, Rwampara, and Bunia health zones in Ituri province, a region already destabilized by Islamic State-backed militant attacks that complicate containment efforts.

“Every day, people are dying … and this has been going on for about a week,” said Jean Marc Asimwe, a resident of the provincial capital Bunia. “In a single day, we bury two, three or even more people. At this point, we don’t really know what kind of disease it is.”

The Bundibugyo strain of the Ebola virus was identified in eight of 13 blood samples tested at the National Institute of Biomedical Research, Health Minister Samuel-Roger Kamba said Friday. The remaining five samples could not be analyzed due to insufficient volume. The suspected index case is a nurse who died at a Bunia hospital on April 24 with symptoms suggestive of Ebola, Kamba said, though he did not say whether that nurse’s samples were tested.

First cases emerged in the Mongwalu health zone, a high-traffic mining area, and patients seeking care subsequently brought the virus to Rwampara and Bunia, Africa CDC Director-General Jean Kaseya said in an online briefing Saturday. A high number of active cases remain within the community, particularly in Mongwalu, “significantly complicating containment and contact tracing efforts,” Kaseya said.

Insecurity in Ituri, where Islamic State-backed militants carry out frequent deadly attacks, continues to restrict surveillance and rapid-response operations, he added. Of the total deaths, 57 are in Mongwalu, 27 in Rwampara, and three in Bunia.

Uganda’s Health Ministry confirmed Friday that an Ebola case had been “imported” from Congo and that the patient died at Kibuli Muslim Hospital in Kampala on May 14. The body was later returned to Congo and no other local cases have been confirmed. Kenya’s government said Saturday there is only a “moderate risk of importation” due to regional travel and has assembled an Ebola preparedness team while strengthening surveillance at all points of entry.

As Africa’s second-largest country by land area, Congo often faces logistical challenges delivering expertise and supplies to affected regions. Outbreak zones in Ituri lie roughly 1,000 kilometers (620 miles) from the capital Kinshasa and are ravaged by ongoing conflict.

In Bunia, businesses and public activity appeared normal on Friday, but resident Adeline Awekonimungu voiced the anxiety that has settled over the city. “My recommendation is that the government take this matter seriously and that it takes charge of the hospitals so that this matter can be brought under control,” she said.