A second flight will today be sent to evacuate Britons seeking to flee the fighting in South Sudan.
The Foreign Office has strongly advised all remaining British nationals to leave the country amid fears it may prove difficult to get out if there is any further deterioration in the situation.
Fighting has spread through the newly-formed East African state following a reported coup attempt in the capital Juba at the weekend.
One group of British nationals have already left on a Foreign Office flight and a second is due to leave from Juba airport.
Potential passengers were warned that they may not be able to take any luggage on board and may have to leave any bags they bring at the airport.
"The UK plans to send a second flight to South Sudan to evacuate British nationals who wish to leave from Juba airport on Friday December 20, following the evacuation of some British nationals on December 19," a Foreign Office spokesman said.
"We strongly advise all British nationals in South Sudan to leave the country if they can do so safely. You may have difficulty leaving in the event of a further deterioration in security.
"British nationals choosing to remain in South Sudan should remain alert to the local security situation, monitor the media, and stay in a safe location."
The United Nations has estimated that up to 500 people have been killed in fighting between rival factions following a coup attempt against the president by soldiers loyal to his former deputy.
British nationals seeking to leave South Sudan were urged to contact the Foreign Office in London for advice on +44 207 008 1500 or by emailing email@example.com.
The Ministry of Defence confirmed it would send a second C-17 sortie to evacuate Britons from the country.