CONAKRY, Dec 24 (Reuters) - Thousands of Guineans on Wednesday cheered a young army captain chosen to head a military junta which seized power in a coup following the death of veteran President Lansana Conte, witnesses said. The crowds mobbed a convoy of military vehicles, led by a tank, carrying Capt. Moussa Dadis Camara to the presidency in downtown Conakry where he was due to be installed as de facto head of state of the West African bauxite exporter. Camara, brandishing a Guinean national flag and surrounded by armed soldiers in a military vehicle, waved to the crowd, some of whom shouted "Camara, Obama" in reference to U.S.-president elect Barack Obama. Earlier, Camara was chosen to head the military junta, the National Council for Democracy and Development, which on Tuesday announced the suspension of the constitution and the government following Conte's death from illness on Monday. (For full Reuters Africa coverage and to have your say on the top issues, visit: http://africa.reuters.com/) (Reporting by Saliou Samb; Writing by Pascal Fletcher)