BUNIA, Congo — Health care workers and aid groups in eastern Congo said Thursday they are in dire need of more supplies and staff to respond to a growing Ebola outbreak linked to a rare virus, as armed groups continue to threaten a region already grappling with a displacement and humanitarian crisis.

“The situation is worrying because this is gaining momentum,” Hama Amado, a field coordinator in the city of Bunia for the Alima aid group, told The Associated Press. “This is spreading in many areas. So everyone must mobilize.”

He added: “We are still far from saying that the situation is under control.”

There is no available vaccine or medicine for the Bundibugyo strain responsible for the outbreak, which spread undetected for weeks following the first known death while authorities tested for a more common Ebola virus.

Health care workers and aid groups are struggling to respond as experts say the outbreak is much larger than what has been officially reported. Authorities have so far announced 139 suspected deaths and nearly 600 suspected cases.

On Thursday, the M23 rebel group that controls parts of eastern Congo reported a confirmed case near the major city of Bukavu, some 310 miles south of the outbreak’s epicenter in Ituri Pronvince. The person died, M23 said in a statement.

As well as Ituri, other cases have been confirmed in North Kivu province and two in Uganda. But the announcement by M23 was the first confirmation of a case in South Kivu.

Health officials have not yet found “patient zero,” according to the World Health Organization, which has said that the threat of a global spread of the outbreak is low.

The outbreak in Congo has had wider repercussions.

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.

Early detection is key

While almost 20 tons of aid has been airlifted to Bunia, the site of the first known death last month, doctors using out-of-date facemasks were tending to suspected Ebola patients in general wards because of the lack of isolation space.

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, according to the U.N.

“Communities in eastern DRC are already facing immense pressure from conflict, displacement, and a collapsing health system,” said Dr. Lievin Bangali, Senior Health Coordinator for the International Rescue Committee in DRC. “Years of underfunding, compounded by recent cuts to front line health and outbreak preparedness programming, have weakened the ability to detect and respond to outbreaks quickly.”

The group said it had to stop its surveillance activities in three out of five areas in Ituri over the last year because of funding cuts.

A mother watches her son ‘bleeding and vomiting’

At a treatment center in Rwampara, near Bunia, health care workers in protective gear handled the bodies of suspected Ebola victims.

Families who tend to wash loved ones’ bodies themselves watched on as workers disinfected the corpses and placed them into coffins to be taken to secure burial sites. Some relatives burst into tears.

The disease struck suddenly, they said, describing a rapid deterioration after symptoms were mistaken for illnesses such as malaria.

“He told me his heart was hurting,” said Botwine Swanze, who lost her son. “Then he started crying because of the pain. Then he started bleeding and vomiting a lot.”

The Ebola virus 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.

‘We have no protection’

Schools and churches remain open in Bunia. Some residents have started wearing facemasks, which have become harder to find.

“It’s truly sad and painful because we’ve already been through a security crisis, and now Ebola is here too,” said Justin Ndasi, a resident.

A Doctors Without Borders team identified suspected cases over the weekend at the city’s Salama hospital but found no available isolation ward in the area, Trish Newport, an emergency program manager, said on social media.

“Every health facility they called said, ‘We’re full of suspect cases. We don’t have any space.’ This gives you a vision of how crazy it is right now,” she said.

In Bambu General Hospital elsewhere in Ituri, suspected Ebola patients shared a ward with others.

In Mongbwalu, where the body of the first known death was taken, the nearby border with Uganda remains open and gold mining continues, said Chérubin Kuku Ndilawa, a civil society leader, highlighting the difficulty of containing the virus.

At Mongbwalu General Hospital, Dr. Didier Pay said they were treating around 30 Ebola patients. A student from the local medical technology institute died on Wednesday.

“The patients are scattered here and there in rather unusual conditions,” Dr. Richard Lokudu, the hospital’s medical director, told the AP. He said if they didn’t get help setting up new facilities they could be “completely overwhelmed.”

WHO chief says the ‘scale of the epidemic is much larger’

WHO has declared the outbreak a public health emergency of international concern. The organization’s director-general, Tedros Adhanom Ghebreyesus, said he was “deeply concerned about the scale and speed of the epidemic” and it’s likely much larger than the official case count. WHO’s chief in Congo said the outbreak could last at least two months.

Investigations are continuing into the source of the outbreak, but “given the scale, we are thinking that it has started probably a couple of months ago,” said Anaïs Legand, a viral hemorrhagic fevers expert at the WHO.

The London-based MRC Centre for Global Infectious Disease Analysis estimates that cases have been substantially undercounted and that the actual number could already exceed 1,000.

Insecurity continues

Long the scene of attacks by an array of armed groups, the region’s volatility now 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.

Fighters with the Allied Democratic Forces (ADF), which has ties to IS, killed civilians with machetes and firearms, burned down houses and business and took several people hostage. Civil society groups warned of other villages in the region facing a threat of attack.

The number of ADF fighters in Congo is unclear, but they are a significant presence in the region and regularly attack civilians. Another armed group that is active in the region is CODECO, a loose association of militia groups.

Ladd Serwat, a security analyst, said he would be “especially worried about an opportunistic attack on health care workers” if the outbreak spreads into rebel areas.