BUNIA, Democratic Republic of the Congo — People set fire to an Ebola treatment center in a town at the heart of the outbreak in the Democratic Republic of the Congo on Thursday after being stopped from retrieving the body of a local man, a witness and a senior police officer said, as fear and anger grow over a health crisis that doctors are struggling to contain.The arson attack in Rwampara reflects the challenges of health workers trying to curb a rare Ebola virus by using stringent measures that might clash with local customs, such as burial rites. The disease has been spreading for weeks in a region lacking in adequate health facilities and where many people are on the move to escape armed conflicts.The bodies of those who die from Ebola can be highly contagious and lead to further spread when people prepare bodies for burial and gather for funerals. The dangerous work of burying suspected victims is being managed wherever possible by authorities, which can be met by protests from victims’ families and friends.The center in Rwampara was burned by local youths who became angry while trying to retrieve the body of a friend who had apparently died of Ebola, according to a witness who spoke to The Associated Press by telephone.“The police intervened to try to calm the situation, but unfortunately they were unsuccessful,” said Alexis Burata, a local student who said he was in the area. “The young people ended up setting fire to the center. That’s the situation.”An Ebola isolation site is set on fire in Rwampara town, Democratic Republic of Congo, on May 21.Str / Xinhua News Agency via Getty ImagesAn AP journalist saw people break into the center and set fire to objects inside and also to what appeared to be the body of at least one suspected Ebola victim that was being stored there. Aid workers fled the treatment center in vehicles.Deputy Senior Commissioner Jean Claude Mukendi, head of the public security department in Ituri Province, said the youths had not understood the protocols for burying a suspected Ebola victim.“His family, friends, and other young people wanted to take his body home for a funeral even though the instructions from the authorities during this Ebola virus outbreak are clear,” Mukendi said. “All bodies must be buried according to the regulations.”Hama Amadou, field coordinator for the humanitarian organization ALIMA, which had teams working at the center, said later that calm had been restored and that aid teams were continuing their work at the center.The flash of anger underlined the complications faced by both Congolese authorities and an array of aid agencies trying to stem the outbreak.The World Health Organization chief said Friday that the Ebola outbreak in Congo is spreading rapidly and now poses a “very high” risk there, as a lack of medical resources and anger among the population hamper the response in a vulnerable and conflict-ridden region.WHO Director-General Tedros Adhanom Ghebreyesus said the risk of global spread remains low, but that the U.N. health agency was revising upward its assessment of the risk within Congo from its previous categorization of “high.”The WHO chief noted that 82 cases have been confirmed in Congo, with seven confirmed deaths, though he said the outbreak is believed to be “much larger.” He said there are now almost 750 suspected cases and 177 suspected deaths.02:06What to know about the Bundibugyo Ebola outbreak00:0000:00Supplies were being rushed to Ituri province in the northeastern corner of the country, where the illness has been spreading for weeks in areas were many people have been displaced by armed conflict.Frontline medical staff have struggled with a lack of resources and, in some cases, pushback due to what has been characterized as misinformation or situations where medical policy has clashed with local customs such as burial rites.“We are still in the phase where we are intensifying the investigation, searching for cases,” said Jean Kaseya, Director-General of the Africa Centers for Disease Control and Prevention. “I expect the number of cases to increase as surveillance becomes more and more rigorous.”Early detection of the virus is key in saving lives, but the region’s already weak health infrastructure and surveillance capacity has been further weakened by international aid cuts, experts say. There are over 920,000 internally displaced people in Ituri Province, according to the U.N.Armed conflict in the region further complicates efforts to handle the crisis. Local leaders said an attack by militants linked to the Islamic State group killed at least 17 people on Tuesday in Alima, a village in Ituri.Health workers and aid groups have said they are in dire need of more supplies and staff to respond. Also, there is no available vaccine or medicine for the Bundibugyo strain responsible for the outbreak.An expert said this week it would be at least six to nine months before one would be available.“The priority now is to act quickly and work closely with communities, as the coming days are critical,” said Ariel Kestens, the head of the International Federation of Red Cross and Red Crescent Societies delegation in Congo.Ebola is highly contagious and spreads in people through contact with bodily fluids such as vomit, blood, feces or semen. Symptoms include fever, vomiting, diarrhea, muscle pain and at times internal and external bleeding.On Thursday, the M23 rebel group that controls parts of eastern Congo reported that a person had died of the disease near the city of Bukavu, some 500 kilometers (310 miles) south of the outbreak’s epicenter in Ituri Province.It was the first case confirmed in South Kivu Province, and another case was reported there later in the day. Previously, cases had been reported only in Ituri and North Kivu provinces and in neighboring Uganda.The virus spread undetected for weeks following the first known death in late April as Congolese health authorities tested for a different Ebola virus more commonly responsible for outbreaks in the country. Health officials have not yet found “patient zero,” according to the WHO.The scale of the outbreak so far suggests it “started probably a couple of months ago,” said Anaïs Legand, a viral hemorrhagic fevers expert at the WHO.India and the African Union said Thursday that the India-Africa Forum Summit, scheduled to be held next week in New Delhi, had been postponed due to the “evolving health situation in parts of Africa.”On Wednesday, Congo’s soccer team canceled a three-day World Cup preparation training camp and a planned farewell to fans in the capital Kinshasa because of the Ebola outbreak.The U.S. government has placed restrictions on any travelers who have visited Congo, Uganda or South Sudan in the previous 21 days, barring foreign visitors among them from entering the U.S. and requiring U.S. citizens and permanent residents to be diverted to Washington Dulles International Airport for screening.