The incumbent president of Guinea-Bissau Jose Mario Vaz votes at a polling station near the presidential palace in Bissau, Guinea-Bissau, Dec. 29, 2019. Guinea-Bissau's presidential election runoff kicked off here on Sunday between two former prime ministers, Domingos Simoes Pereira and Umaro Sissoco Embalo. (Xinhua/Xing Jianqiao)