Tanzanian health authorities have cautioned people living in regions neighbouring the Democratic Republic of Congo (DRC) following the outbreak of Ebola haemorrhagic fever in the central African country.

Western Tanzanian regions bordering DRC include Mbeya, Rukwa, Kigoma and Kagera.

"All regional medical officers have been instructed to keep on alert because people from eastern parts of DRC enter into Tanzania through the four regions," Wilson Mukama, Permanent Secretary in the Ministry of Health and Social Welfare, said in a statement.

Meanwhile the UN World Health Organization (WHO) clarified that while the latest figures released by various sources mention 375 cases and 167 deaths in western Kasai Province of DRC, the cause of death cannot be confirmed yet.

Of all of these cases and deaths, only one confirmed case of Shigella and less than 10 of Ebola have been registered.

"Everything else still remains to be investigated," Gregory Hartl, WHO communications advisor, said from Geneva. WHO's team in the area and its operations, he added, were growing by the day. "WHO is coordinating the international response, at the behest of the DRC ministry of health."

Approximately 1,850 cases, with over 1,200 deaths, have been documented since the Ebola virus was first identified in the western equatorial province of Sudan, and in a nearby region of DRC in 1976, after significant epidemics in Yambuku, northern DRC and Nzara in southern Sudan.

Ebola, a haemorrhagic illness, which causes death in 50-90 percent of cases, is transmitted by direct contact with the blood, secretions, organs or other bodily fluids of infected persons.

It is characterised by the sudden onset of fever, intense weakness, muscle pain, headache and sore throat. This is often followed by vomiting, diarrhoea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding.