Nigeria's President Muhammadu Buhari and three other West African leaders are due to arrive in Gambia to persuade outgoing leader Yayha Jammeh to accept election defeat. Jammeh, who has been in power since 1994, lost to Adama Barrow of the United Democratic Party (UDP) opposition party during presidential election held on 1 December.

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Barrow, a former businessman who worked as a security guard at an Argos store in London, was appointed as the head of a coalition of opposition parties earlier this year.

Jammeh originally conceded defeat, but he later claimed he intended to contest the outcome of the vote at the Supreme Court due to "unacceptable abnormalities".

Buhari is expected to arrive in Gambia on 13 December, along with Liberia's President Ellen Johnson Sirleaf, a Noble peace laureate and chair of the Economic Community Of West African States (Ecowas) and Sierra Leone's President Ernest Bai Koroma. Ghana's John Mahama, who lost the presidential election last week and conceded defeat, has already arrived, according to Reuters. Macky Sall, President of Senegal, which entirely engulfs Gambia, is not part of the delegation. The two countries have a history of poor relations.

Earlier this month, Senegal called for an emergency meeting of the UN Security Council after Jammeh announced he intended to challenge the election outcome.

Both the Gambia's opposition coalition and president-elect Barrow have urged Jammeh to step down and accept the election result.

Jammeh's U-turn has created a climate of fear in Gambia, where people widely celebrated Barrow's election hoping it could end decades of alleged persecutions and human rights abuses.