Ebola deaths pass 300 in West Africa - WHO

There is no known cure or vaccine for Ebola

The number of people killed by the deadly Ebola virus in West Africa has risen to 337, the World Health Organization (WHO) has said.

Fourteen deaths and 47 new cases were reported across the region over the last week, it added.

Guinea is worst-affected with 264 Ebola-related deaths. In Sierra Leone, there have been 49 deaths and in Liberia 24, the WHO said.

The three countries have been battling to contain the outbreak since February.

The outbreak began in southern Guinea's Guekedou region, but then spread to its neighbours.

'Unmarked borders'

More than 500 suspected or confirmed cases of the virus have been recorded, the WHO said.

There is no cure or vaccine for Ebola - one of the world's deadliest viruses.

It is spread by close contact and kills between 25% and 90% of those infected, depending on the strain of the virus, according to the WHO.

Symptoms include internal and external bleeding, diarrhoea and vomiting.

On Tuesday, Liberia reported the first Ebola-related deaths in its capital city, Monrovia.

Seven people have died there, including a baby and a woman who had come from Sierra Leone, health officials said.

This is the first time an Ebola outbreak has hit multiple locations in three countries, reports BBC International Development correspondent Mark Doyle.

The people who inhabit the region where Guinea, Liberia and Sierra Leone meet are from the Kissy ethnic group and they cross the often unmarked borders freely, to farm and trade.

So maintaining medical controls is a real challenge, our correspondent says.

The WHO said it was working with the three countries to strengthen cross-border collaboration aimed at tackling the outbreak.

It does not recommend any travel or trade restrictions on the three countries, the WHO added.

Ebola virus disease (EVD)

• Symptoms include high fever, bleeding and central nervous system damage

• Fatality rate can reach 90%

• Incubation period is two to 21 days

• There is no vaccine or cure

• Supportive care such as rehydrating patients who have diarrhoea and vomiting can help recovery

• Fruit bats are considered to be the natural host of the virus