MANAGUA, Oct 21 (Reuters) - Nicaraguan police detained the two top executives of the nation"s largest business association on Thursday, amid a wave of arrests ahead of Nov. 7 elections in which President Daniel Ortega will seek a fourth consecutive term, according to the association and authorities. The Superior Council of Private Enterprise (COSEP) president, Michael Healy, was detained after leaving an interview at the attorney general"s office, and its vice president, Alvaro Vargas, was arrested at home. Both men are members of the Civic Alliance, an opposition group that has suffered the arrest of two presidential candidates. The executives are accused of "laundering money, property and assets to the detriment of the Nicaraguan state and society," as well as calling for foreign intervention and sanctions against Nicaragua, local police said in a statement. Ortega"s government has become increasingly isolated and criticized internationally for its crackdowns against the president"s opponents and critical media in the Central American country he has dominated since returning to power 15 years ago. Since June police have detained some 38 opposition leaders, including presidential hopefuls. COSEP in a statement demanded the immediate release of its members and described the detentions as "illegal" and "arbitrary." "These repressive actions by the government are a direct attack on COSEP and its main leaders, which does not contribute to the peace and security that all citizens yearn for," said the association. "Nicaragua needs respect for human rights and democracy." Nicaraguans will head to the polls on Nov. 7 to elect the nation"s president, vice president, and renew Congress. Ortega, who first governed as president between 1985 and 1990, was again elected president in 2007 and has served since then. The Organization of American States (OAS) on Wednesday expressed "alarm" over Nicaraguan government actions it says will undermine the elections. The OAS permanent council adopted a resolution to urge fair elections and the release of presidential candidates and political prisoners. read more