“Can it be that they want to see the cadaver with four bullets in it?” he said, knocking on a wooden table to ward off bad luck. “That’s the proof they want to see.”

Mr. Maduro said the refinery explosion in August 2012, which was caused by a gas leak, was carried out to disrupt the country before an election last October in which Mr. Chávez was re-elected, suggesting that it was done at the prompting of the American Embassy. The country’s enemies are also plotting to bring down the economy, he said.

Venezuela is struggling with inflation that is running at more than 45 percent a year, with chronic shortages of staple foods and basic consumer goods in the stores. Many economists say that government price controls and a lack of dollars to pay for imports are causing those problems.

But Mr. Maduro insisted that they were the result of a “war against the economy,” saying that he had the names of businessmen who were conspiring to further reduce the supply of some products, aiming to cause “a calamitous situation” this fall.

He also claimed to have information of a meeting in the White House in late July in which officials from the State Department, the National Security Agency, the C.I.A. and the Pentagon came up with a plan called “Total Collapse” intended to destabilize Venezuela.

“There could be people who think that this is fantasy,” Mr. Maduro said. Invoking Salvador Allende, the leftist Chilean president who was overthrown in 1973 after concerted American attempts to undermine him, he said, “It is raw reality.”

Mr. Maduro’s fiery words create the impression that he is surrounded on all sides by enemies who want to take away the social programs and other benefits provided by his government to the poor.