The World Health Organization (WHO) warned Friday that the outbreak of the deadly virus Marburg which has killed 174 people in Angola is not yet under control.

"The situation right now in Angola is not under control yet," Mike Ryan, head of the WHO's emergency response unit, told reporters here.

He asked international agencies and local health authorities to remain firmly engaged in Angola for the next four to six weeks to control the epidemic.

"This is still a crisis, and a health crisis at the national level, and requires a profound commitment from national authorities and the international community," he said.

On Thursday, the WHO recommended that four nearby countries -- Congo, Democratic Republic of Congo, Namibia and Zambia -- go on alert following the outbreak of deadly Ebola-like disease.

The death rate is unusually high among the 200 cases identified since last October, and the victims are mainly children under five.

Marburg hemorrhagic fever is characterized by headache, nausea, vomit and bloody diarrhea. It spreads through close contact with bodily fluids including blood, saliva and semen.

Scientists from laboratories in Canada, Germany, South Africa and the United States are collaborating to help analyze samples taken from victims and interpret results, the WHO said in a statement.

Source: Xinhua