Updated

The president of West Africa's regional bloc says that Gambia could be plunged into violence by the president's decision to reject election results in which he was defeated after 22 years in power.

ECOWAS president Marcel Alain de Souza said late Sunday that President Yahya Jammeh must respect the Gambian people's choice, calling Jammeh's about-face shameful to the regional community. He spoke in Maiduguri, saying Gambia now adds to the challenges in West Africa, including Nigeria's Boko Haram insurgency and extremist attacks in northern Mali.

The Gambian president initially conceded defeat to president-elect Adama Barrow after the Dec. 1 elections. But on Friday, Jammeh rejected the results. His party says it will file an appeal.

International, regional bodies and governments have joined in calls for Jammeh to step down.