The government of Sao Tome and Principe on Thursday fixed the second round of a presidential election for August 7 despite unrest after a challenge to the first-round result. The ruling party candidate and former prime minister Evaristo Carvalho appeared to have scraped past the required 50-percent mark needed for an outright win in the July 17 poll. But incumbent Manuel Pinto da Costa challenged the outcome and election officials in Africa’s second smallest state called a second round after revising Carvalho’s tally to 49.8 percent and 24.83 for Da Costa, the candidate of Prime Minister Patrice Trovoada. Carvalho, standing for the Independent Democratic Action party, had initially been credited with a 50.2 percent score.