Relief charity Merlin has begun operating in rebel-held areas of Liberia, providing emergency medical services in the south-east of the country.
Doctors from the charity are working at three clinics in Zwedru, which is the main area for rebel Movement for Democracy operations in the south-eastern region and other areas. There are also plans for a needs assessment in Nimba county, where there is currently still fighting.
Dr Clement Peter, Merlin's medical co-ordinator in Liberia, said: "With large swathes of the population in these counties unable to access any healthcare, it is urgent that we respond quickly to re-establish primary health services and get drugs and equipment to areas where they are needed."
A spokeswoman for Merlin said that the charity did not anticipate attacks on staff because the security situation has stabilised.
Two years ago, two Merlin staff were kidnapped in Liberia but subsequently released.