Venezuelan opposition candidate Henrique Capriles -- believed to be the target of an alleged assassination plot by the U.S. government.<br/> <br />He kicked off his election campaign last weekend ahead of the country's April 14 vote following the death of former President Hugo Chavez.<br/> <br />But acting President Nicolas Maduro, Chavez's preferred successor as president, says the U.S. is behind a plot to assassinate Capriles-- to sow chaos in the state and trigger a coup.<br/> <br />In an interview on Sunday, he called on President Barack Obama to stop the alleged plan, laying the blame on former Bush administration officials Roger Noriega and Otto Reich.<br/> <br />Both rejected the claim as untrue, outrageous and defamatory.<br/> <br />During his 14 years in power, Chavez often denounced U.S. plots against him and his revolution.<br/> <br />Critics dismissed those claims as a smokescreen to keep voters focused on a sense of imperialist threat.<br/> <br />Capriles has said Maduro would be to blame if anything happen