GUATEMALA CITY: Thousands of Guatemalans Saturday waved flags, chanted and demanded that President Otto Perez resign, in a graft scandal that has already seen his vice president step down. Perez refused to resign earlier, just hours after he was accused of being a leader of the corruption scandal that has rocked his country, his spokesman said. With just over two weeks to go to general elections, prosecutors and officials from a UN investigative commission said they had uncovered extensive evidence implicating Perez and Vice President Roxana Baldetti in a massive, highly organized scheme to reduce importers’ customs duties in exchange for bribes. Baldetti resigned, and was then arrested Friday. Business leaders issued a call for Perez to stand down immediately.