The Economic Community of West African States says the Ebola epidemic known to have spread to Guinea's capital is "a serious threat to regional security".
Guinea's capital is on high alert after a deadly Ebola epidemic that has killed dozens in the southern forests was confirmed to have spread to the sprawling port city of two million people.
Eight cases have been confirmed in the capital Conakry, the Guinean health ministry said on Friday, including one fatality.
All those infected with the highly contagious virus have been put into isolation at the capital's biggest hospital.
Aid organisations have sent dozens of workers to help the poor west African country combat the outbreak of haemorrhagic fever.
The health ministry said 111 cases of haemorrhagic fever, including 70 deaths, had been recorded from January to March 28, a fatality rate of 63 per cent.
Most of the cases were recorded in southern Guinea, but in the past two days, it has spread to the capital.
Residents of Conakry's suburbs told AFP they feared venturing into the city centre to shop and were keeping their children home from school.
"I wonder what Guinea has done to God to make him send us this untreatable disease ... I'm wary of anything that moves that could be a carrier of the disease," unemployed graduate Abdoulaye Soumah said.
The 15-member Economic Community of West African States (ECOWAS) said the outbreak was "a serious threat to regional security" and appealed for help from the international community.
The tropical virus causes severe fever and muscle pain, weakness, vomiting, diarrhoea and, in severe cases, organ failure and unstoppable bleeding.
Further suspected cases being investigated in Liberia and Sierra Leone could push the total death toll beyond 80.
Transmission of Ebola to humans can come from wild animals, direct contact from another human's blood, faeces or sweat, as well as sexual contact or the unprotected handling of contaminated corpses.
The health charity Doctors Without Borders, known by its French initials MSF, said the spread of the disease was being exacerbated by people travelling to funerals in which mourners touch the bodies of the dead.
Guinea has banned the consumption of bat soup, a popular delicacy in the country, as the fruit bat is believed to be the host species.