Opposition leaders countered that it's reasonable to expect that both campaigns can hold events peaceably on Tuesday in the state of Barinas, where the late President Hugo Chavez was born.
Campaigning in Barinas, Maduro told a crowd of supporters that opposition candidate Henrique Capriles' decision to campaign in the city of Barinas, the state capital, was a "provocation," especially because Maduro had announced plans to campaign the state by bus that day. It was unclear so far whether the candidates would be campaigning in the same city at the same time Tuesday.
Maduro urged his followers to resist the temptation to fall into violence.
"They have decided to commit the first act of violence on Tuesday, here in Barinas. That's why (Capriles) decided to come here, to provoke the people," Maduro said. "I have proof of what they're planning."
However, Maduro offered no details Saturday.
During a heated and often personal campaign, Maduro and Capriles have traded insults, and Maduro has occasionally alluded to plots to destabilize the country, again without any evidence.
Carlos Ocariz, a top adviser to the Capriles campaign, told a news conference that Maduro's statements reflected "nervousness" about the election's outcome.
"We believe that in Venezuela, various political events can be held on the same day" in the same locale, Ortiz said.
Nominally, Tuesday marks the official start of Venezuela's abbreviated campaign before the April 14 election. In reality, the campaign started just days after Chavez's death March 5 from cancer, and it has only intensified since. Both candidates have relentlessly campaigned across the South American country.
Maduro was Chavez's vice president and became acting president after Chavez died. He is seeking outright election to a six-year presidential term.
Capriles is governor of the central state of Miranda. He lost a hard-fought presidential election to Chavez in October.
The city of Barinas is located 390 kilometers (230 miles) southwest of Caracas and is near the plains town of Sabaneta, where Chavez was born in 1954.