It is a "dark day" for everyone fighting the deadly Ebola outbreak after rebels shot and killed two medical agents with the Congolese army, DRC's health minister announced late Saturday.This appears to be the first time health workers have been killed by rebels in this outbreak, which is taking place in what has been compared to a war zone. Multiple rebel groups are active in DRC's far northeast.Mai Mai rebels surged from the forest and opened fire on the unarmed agents with the army's rapid intervention medical unit at an entrance to Butembo city, the health ministry said.The daytime attack appeared premeditated, with civilians present left unharmed, the statement said. The medical agents had been placed in "dangerous zones" to assist national border health officials.Confirmed Ebola cases have now reached 200, including 117 deaths. Aid groups have expressed alarm after the insecurity and sometimes hostile community resistance led the rate of new cases to more than double this month.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and FacebookHealth workers in this outbreak, declared on August 1, have described hearing gunshots daily, operating under the armed escort of UN peacekeepers or Congolese security forces and having to end work by sundown to lower the risk of attack.DRC's health ministry has reported "numerous aggressions" against health workers, and early this month two Red Cross volunteers were severely injured in a confrontation with wary community members in a region traumatised by decades of fighting and facing an Ebola outbreak for the first time.A deadly rebel attack against civilians in Beni late last month forced the suspension of Ebola containment efforts for days, and the effects are still seen. Many of the new confirmed cases this month, including six reported on Saturday, have been in Beni, where most of the Ebola work is based."Health agents are not a target for armed groups," Health Minister Oly Ilunga said. "Our agents will continue to go into the field each day to fulfill the mission entrusted to them. They are true heroes and we will continue to take all necessary measures so that they can do their job safely."Co-ordinated response On Wednesday, the World Health Organisation said it was "deeply concerned" by the outbreak but that it does not yet warrant being declared a global emergency. An outbreak must be "an extraordinary event" that might cross borders, requiring a co-ordinated response. Confirmed cases have been found near the heavily traveled border with Uganda.In the latest sign of the rumors that pose another serious challenge to containing the deadly virus, the health ministry said 22 youth in Butembo dug up the body of an Ebola victim and opened the body bag, "wanting to verify that no organs had been taken from the body by health workers."They ended up touching the highly infectious bodily fluids, the ministry said. "The next day, they agreed to be vaccinated," joining the more than 20 000 people who have received vaccinations so far.