CARACAS — Venezuela's opposition on Thursday warned of a possible mass exodus of migrants if President Nicolas Maduro remains in power following his disputed reelection, as the US called on the dictator not to arrest protest leaders.

Washington has spearheaded sanctions against the Maduro regime and on Thursday threatened that further measures would be taken if Maduro were to arrest opposition leaders Machado or Edmundo Gonzalez Urrutia, a retired diplomat who stood as a candidate after agreeing at the last minute to replace his barred colleague.