The fight against the Ebola outbreak in the Democratic Republic of Congo is at a "critical juncture" after attacks on civilians forced the suspension of control activities, a senior World Health Organization official has warned.
"We are now extremely concerned that several factors may be coming together in the next weeks or months to create a potentially ideal storm".
This latest outbreak in the country's east has infected at least 118 people, including 69 people who have died, according to Congo's Health Ministry.
Some people were fleeing into the forest to escape Ebola follow-up treatment and checks, sometimes moving hundreds of kilometres, he said.
Beni is a key hub for WHO's North Kivu operations.
In the almost two months since the outbreak was declared, there have been 150 confirmed and probable cases of the disease, and 100 people have died, as of 23 September.
The attack underscores the challenges the government and health organisations face in tackling Ebola in an area where years of instability has undermined locals' confidence in the authorities.
One of the armed groups in DRC which pose a threat to civilians and the worldwide response to Ebola, the ADF - Allied Democratic Forces - has sufficient military capacity to ambush blue helmets from the UN'a Stabilization Mission in DRC (MONUSCO) and government forces - the FARDC.
In a second tweet, Salama communicated that the Ebola response teams in the city of Beni were on lockdown beginning Sunday. "That resistance, driven by quite natural fear of this terrifying disease, is starting to be exploited by local politicians, and we're very concerned in the run up to elections, projected for December, that that exploitation. will gather momentum and make it very hard to root out the last cases of Ebola". Ebola's symptoms include high fever and vomiting, which make it hard to treat, because it resembles many other illnesses in its early stages.
A Uganda-based rebel group called the Allied Defense Forces has been especially destructive, Salama said. More than 10,000 people have since been vaccinated.
"We will not yet consider the need to evacuate but we are developing a range of contingency plans to see where our staff are best located", he said.