Experimental Ebola drugs, including compounds from Mapp Biopharmaceutical, Sarepta and Tekmira, will be tested in West African states for the first time in a bid to fast-track trials, the Wellcome Trust said on Tuesday.

Announcing a 3.2-million-pound ($5.25 million) grant for the work, the global health charity said the money would "enable multiple partners around the world to quickly establish clinical trials at existing Ebola treatment centers".

The World Health Organization said up to 20,000 people could be affected before the Ebola plague is brought under control.

The outbreak of the virus, one of the most virulent infectious diseases known, has been declared a threat to international peace and security by the UN Security Council and has prompted demands for an urgent response.

In August, a WHO expert panel unanimously concluded that in such extraordinary circumstances it would be ethical to deploy and test unregistered experimental treatments on people with Ebola.

"It is a huge challenge to carry out clinical trials under such difficult conditions, but ultimately this is the only way we will ever find out whether any new Ebola treatments actually work," said Jeremy Farrar, the Wellcome Trust's director.