By Samuel Elijah COTONOU, May 14 (Reuters) - Benin's presidential guard killed two people and injured at least five when they fired on townspeople who were angry about a road staying blocked after the president's car had passed, officials said on Monday. The incident took place on Sunday at Ouidah, 35 km (22 miles) west of the capital Cotonou, after President Thomas Boni Yayi's convoy had already driven through the town. "People did not want to obey the orders of presidential security ... A taxi driver and a motorbike taxi driver were killed on the spot and others were taken to hospital," one witness, journalist Antoine Kpotcheme, said. Local residents looted and burned security forces' vehicles after the shootings, witnesses said. Security around Yayi had been tightened after gunmen ambushed his convoy in March, ahead of a election which gave his coalition control of parliament in the cotton-producing West African country. Yayi was unhurt in that attack, which he blamed on enemies opposed to his efforts to stamp out corruption. Public Security Minister Edgard Alia confirmed the deaths and injuries and said an investigation had been opened in the former French colony, broadly seen as a stable state in a troubled region. "The head of state is deeply saddened by the tragedy," Alia said in comments cited on Monday by state media. Yayi, a former development banker elected a year ago, has made tackling corruption a major part of his declared campaign to revitalise Benin's economy as it wrestles with low prices for its main export, cotton.