Hugo Chavez dead Venezuelan president Hugo Chavez has died, according to a national televised address by his vice-president Nicolas Maduro. Chavez, who had been battling cancer for two years, had not been seen in public nor heard from since undergoing surgery in Cuba on December 11, his fourth operation since the disease was detected in his pelvic area in mid-2011. The 58-year-old left-wing firebrand was adored by many poor Venezuelans for his humble roots, earthy rhetoric and welfare policies financed by the country's dominant oil industry. But opponents viewed him as a dictatorial leader who ruined the nation's economy. Dead ... Hugo Chavez. Timeline of Hugo Chavez's life The announcement of his death came less than 24 hours after his deputy claimed Chavez had been infected with cancer by "imperialist" enemies. His prolonged absence - which prevented him from being sworn in to a new six-year term earlier this year - angered the opposition, which had accused the government of lying about his condition. President Hugo Chavez ... adored by many poor Venezuelans. In recent months, the Venezuelan government was repeatedly forced to deny speculation, particularly among pro-opposition media, that Chavez may already be dead. Chavez had in the past undergone several grueling rounds of chemotherapy and radiation treatment, which at times left him bald and bloated. He twice wrongly declared himself cured. Dozens of student demonstrators had been holding protests around Venezuela, including chaining themselves up, to demand proof Chavez is alive and more medical details. Friends ... Fidel Castro, left, talks with Hugo Chavez. "The lack of precise information worries Venezuelans and contributes to the rumors," said Ramon Guillermo Aveledo, executive-secretary of the opposition Democratic Unity coalition. He lambasted the government's aggressive line toward opposition politicians in recent days. It is expected an election would be held within 30 days and would probably pit Maduro against opposition leader Henrique Capriles for leadership of a nation with the world's biggest oil reserves. Polls show Maduro is the favourite, helped by Chavez's personal endorsement as his successor. A man walks past a mural portraying the Venezuelan flag, President Hugo Chavez and South American liberator Simon Bolivar. The stakes are high, too, for other left-leaning nations around Latin America and the Caribbean. Chavez's oil-financed largesse has boosted economies of allies from Cuba and Nicaragua, to Bolivia and Ecuador. Imperialist plot Vice President Maduro's earlier accusations and somber prognosis came during a televised meeting of political and military leaders at the presidential palace. Hugo Chavez hugs his daughters Rosa and Maria. "We have no doubt that commander Chavez was attacked with this illness," Maduro said, repeating a charge first made by Chavez himself that the cancer was an attack by "imperialist" foes in the United States in league with domestic enemies. "The old enemies of our fatherland looked for a way to harm his health," Maduro said, comparing it with allegations that Palestinian leader Yasser Arafat, who died in 2004, may have been poisoned by Israeli agents. Alleging a plethora of conspiracies from abroad and inside Venezuela, Maduro said the US Embassy's Air Force attache was expelled from the country for allegedly trying to stir up a military plot against the government. Supporters of Venezuelan President Hugo Chavez pray in a chapel outside the Caracas military hospital in Caracas. A US Defence Department spokesman identified him as Colonel David Delmonaco and said he was en route to the United States. Foreign Minister Elias Jaua later said two US diplomats had been expelled in the latest flare-up between the two ideologically opposed governments. "Our supreme responsibility is to keep telling our people the truth," said Maduro, surrounded by grim-faced officials including Chavez's elder brother Adan, a state governor. Maduro and other senior officials have been haranguing the opposition daily as "fascists" and "conspirators" exulting in Chavez's suffering and plotting to destabilise Venezuela. Though Chavez has always paid the country's obligations even while railing against capitalism, the prospect of a change in government has led to rising prices on Venezuelan sovereign and state-run oil company Petroleos de Venezuela (PDVSA) debt. With Maduro seen as the probable winner in an election, most market players are factoring in a continuation of "Chavismo."