The World Health Organization (WHO) has given a serious warning after a big increase in suspected Ebola cases in the Democratic Republic of Congo. In one week, reported infections rose from 246 to almost 750. The virus has now reached large cities such as Goma and has appeared in nearby Uganda, making the outbreak harder to control.

This outbreak is from the Bundibugyo strain of Ebola, which scientists say is rare. There is no approved vaccine or specific treatment for this strain, so health workers must use strict isolation and other usual methods to stop the virus spreading further.

Because Ebola is moving across borders and into heavily populated areas, health officials say it is very difficult to manage. The WHO is asking for more money and medical help. Nearby countries have started health checks at borders and built treatment centres to try to stop the outbreak from spreading.