The death toll from the Ebola outbreak in West Africa has passed 3,000, the World Health Organization (WHO) says.

The latest figures indicate that more than 6,500 people are believed to have been infected in the region.

Liberia is the worst affected country, having recorded around 1,830 deaths linked to the latest outbreak.

The outbreak is the world's most deadly - US President Barack Obama has called it a "threat to global security".

The report also mentions the risk of infection for health-care workers trying to stem the outbreak.

It says 375 workers are known to have been infected, and that 211 have so far died from the virus.