BUNIA, Congo — Aid workers rushed supplies Thursday to the center of Congo’s outbreak of a rare type of Ebola virus while beleaguered medical personnel struggled with a lack of equipment, a distrustful population and armed groups in a volatile region.

A white cargo plane with aid donated by the European Union delivered masks, gloves, boots and medications — all of which are in short supply — to the northeastern town of Bunia at the heart of the outbreak in Congo’s Ituri province. U.N.-branded forklifts lifted several cases into trucks.

Health workers with scant supplies have been struggling to contain an outbreak of the Bundibugyo virus, a kind of Ebola that has no approved treatment or vaccine. In some areas, doctors have resorted to wearing expired medical masks while treating suspected patients.

Dangers faced by health workers have been heightened by anger among residents over the stringent medical protocols for dealing with the bodies of victims, which clash with local burial rites. Residents have launched at least three attacks against health centers in Ituri province.

Congolese Health Minister Samuel Roger Kamba said that during outbreaks people in remote communities can feel overwhelmed by an incoming flood of information and people.

“We’ve seen in every epidemic that there’s always resistance,” Kamba said. “Communities always ask themselves, ‘What’s going on?’ And in epidemics like this one, it is really risk communication and community engagement that ultimately change perceptions.”

Aid donated by the EU is expected to arrive in batches over the next eight days, Jérôme Kouachi, head of emergency operations at UNICEF in Congo, told The Associated Press.

World Health Organization Director-General Tedros Adhanom Ghebreyesus was on his way to Congo to see the efforts first-hand. The WHO has declared the outbreak a public health emergency of international concern, in the hope of ramping up aid.

The United States on Thursday said it is increasing its aid to Congo and Uganda by $80 million, bringing its commitment to more than $112 million since the outbreak.

The additional money would pay for personal protective equipment for health care workers, Ebola test kits, support for health screening at airports and contact tracing, the U.S. State Department said.

Dr. Jean Kaseya, the Africa Centres for Disease Control director-general, said that the organization on Monday believed it had secured funding pledges of nearly $500 million toward Africa’s emergency response, but that as of Thursday afternoon the amount had dwindled to $290 million as partners withdrew or reduced pledges.

He also said that the Africa CDC hoped to have treatments and a vaccine for the Bundibugyo virus by the end of the year, and that there were some vaccine candidates already in the works.

The Congolese government has confirmed more than 1,000 suspected cases, with at least 220 deaths, since it declared an outbreak on May 15. But the virus had been spreading undetected for weeks, and the WHO suspects it is much larger than what has been reported.

The virus has also reached neighboring Uganda, which has confirmed seven cases and one death.

On Wednesday, the Congolese government said the first survivor to recover from the virus had left a health center.

“We are trying to catch up,” Congo Foreign Minister Therese Kayikwamba Wagner said earlier this week. “It is a race against the clock.”

The response on the ground has been hampered by multiple challenges, including customs’ red tape, insufficient storage facilities, bad roads and weak telecommunications, humanitarian agencies said in a report on Thursday.