GUATEMALA CITY - Guatemalans voted yesterday in a presidential election that has turned into a barometer of support for a former military dictator, Gen Efrain Rios Montt. Bomb threats marred the start of the second round run off between a right wing businessman, Mr Alvaro Arzu, who narrowly led pre election polls, and a lawyer, Mr Alfonso Portillo, candidate for the populist Guatemalan Republican Front (FRG).