MANAGUA: Nicaraguan police said on Sunday (Monday in Manila) they had detained four more opposition figures in a roundup ahead of November presidential elections in which four would-be challengers of long-serving leader Daniel Ortega have already been held. Those arrested on Sunday were top figures of the Unamos opposition party - its president, Suyen Barahona Cuan, vice president Hugo Torres, ex-guerilla Dora Maria Tellez and Ana Margarita Vigil Guardian, a police statement said. It said the four were being investigated for 'acts that undermine independence, sovereignty and self-determination [and] inciting foreign interference in internal affairs,' among other crimes.