Venezuela's president-elect blamed the opposition Tuesday for seven deaths and 61 injuries that the government claims have occurred in disturbances protesting his election, and he accused the U.S. of organizing the unrest.
Opposition candidate Henrique Capriles later accused the government of being behind the violence.
Maduro's accusation against Washington came after the U.S. State Department said it would not recognize the results of Sunday's unexpectedly close election without the vote-by-vote recount being demanded by Capriles.
"The (U.S.) embassy has financed and led all these violent acts," President-elect Nicolas Maduro, the chosen heir of the late Hugo Chavez, said during a televised meeting at the headquarters of the state oil company.
Earlier, he said he would not allow an opposition protest march called for Wednesday in Caracas, saying Capriles was "responsible for the dead we are mourning" from violence during protests across the country.
Maduro then summoned his own supporters to take to the streets Wednesday in the capital, raising the possibility of a confrontation with anti-government protesters.
But Capriles called off the planned opposition march. "Whoever goes out into the street tomorrow is playing the government's game," he said. "The government wants there to be deaths in the country."
He said the accusation by officials that he is mounting an attempt to overthrow the socialist government is a smoke screen to divert attention from demands for a recount.
"I want to ask Mr. Maduro to calm down a bit. I think he's sort of going crazy," Capriles said at a news conference.
According to the regime-friendly National Electoral Council, which quickly certified Maduro's election Monday, he defeated Capriles by 262,000 votes out of 14.9 million ballots cast. Capriles has charged that Chavistas stole the election.
Outside the capital, a march to demand a recount turned violent in the capital of Barinas,the home state of Chavez. Police fired tear gas and plastic bullets at protesters heeding Capriles' call for protests by marching on the provincial headquarters of the electoral council. Opposition leaders reported 30 arrests. There were no immediate reports of injuries.
Barinas Gov. Adan Chavez is a brother of Hugo Chavez, the charismatic but divisive Venezuelan leader who succumbed to cancer March 5 after 14 years as president.
In a separate televised broadcast, Justice Minister Nestor Reverol accused Capriles of numerous crimes, including insurrection and civil disobedience.
It was part of a drumbeat of attacks by government officials who have been alleging since Monday that Capriles is plotting a coup.
Chief prosecutor Luisa Ortega said 135 people had been detained in protests, presumably on Monday, when Capriles' supporters protested in Caracas and other cities, including Merida and Maracay.
Reverol said one death involved a man in the capital who he charged was shot by opposition supporters. He said other shooting deaths, in the states of Sucre, Tachira and Zulia, were being investigated.
Capriles issued a message on Twitter blaming the government and Maduro for any violence.
"The illegitimate one and his government ordered that there be violence to avoid counting the votes," Capriles tweeted. "They are responsible!"
On Monday, thousands of students briefly clashed with National Guard troops who fired tear gas and plastic bullets while people across the nation banged on pots and pans to demand a recount.
Late Monday, Maduro announced he had met with a newly created "anti-coup" command at the military museum that holds Chavez's remains.
He accused opposition protesters of attacking government clinics and the house of electoral council President Tibisay Lucena, without offering details.
Security analyst Adam Isacson of the Washington Office on Latin America said the tensions increased chances the government might arrest opposition leaders, although he wondered whether security forces would comply with a wave of arrest orders.
He said he was more concerned about "mob violence against opposition figures, and perhaps pro-government ones, too."
Pro-government motorcycle gangs, some of them armed, have in the past threatened and attacked opposition activists.
Serious questions were raised about Maduro's ability to lead after he squandered a double-digit lead in the race despite an outpouring of sympathy for his party following Chavez's death.
Government leaders and military leaders have closed ranks around him.
A hint of discontent did emerge, however, in two Twitter messages by Diosdado Cabello, the National Assembly president who many consider Maduro's chief rival within the "Chavismo" movement.
In the first, he called for a "profound self-criticism" within Chavista ranks. In the second, he wrote: "We should look for our faults under the rocks if we have to."
Diego Moya-Ocampos, an analyst with the London-based consulting firm IHS Global Insight, said members of the ruling socialist party "realize that Maduro is not the man to guarantee continuity of the Chavista movement."
Cabello expressed disbelief at Capriles' strong showing, asking why "sectors of the poor population would vote for their exploiters of old."
That might not be such a mystery.
Among Venezuela's problems are crumbling infrastructure, frequent blackouts, persistent shortages of food and medicine, and double-digit inflation. The nonprofit Venezuelan Violence Observatory estimates Venezuela's homicide rate last year was 73 per 100,000 people, among the world's worst.
With such a narrow victory, Maduro has little political capital to make the difficult choices some of those problems require, said Risa Grais-Targow, Latin America analyst for the Eurasia Group.
Price and currency controls imposed under Chavez have failed to stem inflation or the flight of dollars and are strangling private firms. But lifting them abruptly could bring economic turmoil and hurt the poor.
Grais-Targow said Maduro will likely focus instead on expanding the myriad of social programs that cemented Chavez's popularity. But that has become increasingly difficult to balance with the need to spend money on redressing Venezuela's other problems.
The state-oil company that gave billions of dollars to fund social programs is saddled with mounting debt and declining profits. Critics say the company has failed to invest in boosting oil production, which has fallen for years even though Venezuela has the world's biggest oil reserves.
Maduro's narrow victory has given him little ability to maintain unity in a movement held together largely by loyalty to the charismatic Chavez.
Its factions include former soldiers like Cabello who joined Chavez in a failed 1992 coup. Maduro comes from the ranks of leftist political and labor groups that united to help elect Chavez president in 1998. Chavez's relatives, led by brother Adan, form another bloc.
"His legitimacy comes from the fact that Chavez named him as his successor and other factions were forced to accept it," said Grais-Targow. "But he faces this landscape where the other main figure, Diosdado Cabello, could elevate his role and have more power. There are also governors who have bases of support and could pose challenges."
Still, for now, the powerful state political apparatus built by Chavez is standing with Maduro.
Four of the five directors of the National Electoral Council are pro-government. The Supreme Court is stacked with Chavista sympathizers as are lower courts. The National Assembly is also controlled by Chavistas.
