Venezuela's acting president Nicolas Maduro has accused former US officials Roger Noriega and Otto Reich of plotting to kill him to prevent his victory in next week's presidential elections.
Speaking at a televised campaign event on Saturday, Maduro said the plot also involved
"right-wing forces" from El Salvador, which had already dispatched paid assassins to Venezuela to implement the plan.
"Their goal is to kill me," said Maduro, who had been designated by the late Venezuelan leader Hugo Chavez as his heir apparent.
"They want to kill me because they know they cannot win free and fair elections."
A presidential election to replace Chavez, who died of cancer in March 2013, will be held on April 14.
Maduro said part of the plot also involved sabotaging the nation's electrical grid.
Parts of oil-rich Venezuela suffer from regular power outages, a problem opposition leader Henrique Capriles had seized upon to criticise the socialist government that Chavez led for 14 years until his death on March 5.
On Thursday, Maduro also accused the opposition of plotting to sabotage the national power grid to cause a blackout ahead of the election.
A conservative Mexican-American, Roger Noriega served as US Permanent Representative to the Organisation of American States (OAS) from 2001 to 2003.
Otto Reich, a Cuban-American, was the US president's special envoy for the Western Hemisphere, assistant secretary of state and US ambassador to Venezuela.
While vocal critics of Venezuelan policies, both have repeatedly denied any involvement in Venezuelan affairs.