The government of southern Sudan and international scientists say they are trying to reach a remote village to investigate reports of a possible Ebola outbreak.

The World Health Organization's Global Alert and Response Department in Geneva says it began receiving reports of an outbreak of viral hemmorhagic fever late last month in the village of Kitkit in the under-developed Western Bahr al-Ghazal region of South Sudan.

Villagers in the area say four people have died from the mysterious illness.

The Global Alert and Response Department's leading Ebola scientist, Dr. Pierre Formenty, tells VOA that even though the symptoms may appear to be that of Ebola, scientists will not be able to determine which hemmorhagic virus is causing the disease until they can investigate suspected cases in Kitkit.

Hemmorhagic viruses cause high fever and bleeding from openings in the body.  Some viruses cause relatively mild illnesses, while others such as Ebola and Marburg have high death rates.

Dr. Formenty says because of rain in the area of Kitkit, it is difficult for scientists to reach the village.  He said they need a helicopter to travel to the region and investigate the reports.

The last Ebola outbreak in southern Sudan occurred in 2004.  The disease killed seven people and infected 17 others before it was contained more than a month later.

Ebola is transmitted by direct contact with the blood, secretions, organs or bodily fluids of infected people.     

In another development in Sudan, United Nations agencies and the government in Khartoum say they will begin vaccinating 8.5 million children against polio later this month.  Forty cases of the debilitating disease were reported this year in South Sudan, triggering concerns that the virus could spread into neighboring countries.

Sudan was polio free until 2004, when an outbreak in the north spread worldwide.