Ugandan authorities have begun a clinical trial of a vaccine against the Sudan strain of Ebola that has killed one person in the outbreak declared last week.

The U.S. Centers for Disease Control and Prevention on Thursday warned doctors and other healthcare workers about an outbreak of Ebola cases in Uganda.

Ugandan authorities launched a clinical trial of a vaccine against the Sudan strain of Ebola that has killed one nurse in the capital, Kampala.

Nine people were confirmed to have Ebola virus in Uganda and around 265 others are being monitored under quarantine, health authorities have said. The nine include the first victim, a male nurse who died the day before the outbreak was declared on January 30.