Venezuelan opposition leader Henrique Capriles demanded justice on Sunday for the shooting of three of his activists while President Hugo Chavez promised to run a more efficient government if he wins next weekend's election.
With the South American OPEC member's October 7 presidential vote shaping into a close fight, tensions are high, and the worst violence of the campaign occurred on Saturday when gunmen killed three pro-Capriles activists in Barinas state.
"Yesterday, sadly, violence took three lives, something that should never have happened," Capriles told a vast rally in Caracas that appeared to be the largest of his campaign.
"I want to tell their families, and those angels in heaven, that we are going to defeat violence on the 7th of October."
Capriles' Primero Justicia (Justice First) party said the assailants had fired from a van, which witnesses identified as belonging to a state institution, after Chavez supporters blocked an opposition motorcade.
The government did not confirm that version but promised an investigation into what it said was an isolated incident.
"Anything that harms peace and stability must be condemned," Chavez's campaign chief, Jorge Rodriguez, said.
Venezuela is awash with arms, and voters cite violent crime as their No. 1 worry. There had been some gunshots and clashes at previous opposition rallies but no deaths.
Capriles has hammered Chavez daily on his record with day-to-day problems such as crime, blackouts and shoddy infrastructure - drawing a frank response from the president.
"Efficiency, that is one of my promises for the next period. We have to correct things," the 58-year-old Chavez said on Sunday in his most direct comment on a theme the opposition hopes could sway former "Chavistas" into their camp.
In recent days, Chavez has added into his campaign speeches an acknowledgement of Venezuelans' frustration with grassroots problems but has said things would be far worse under Capriles, who he paints as a heartless capitalist elitist.
Capriles, 40, is a state governor with a centrist vision of a Brazil-style, pro-business government with strong welfare policies.
With one week to go, polls are mixed, leading both sides to claim they are heading for victory. Venezuelans are fearful of violence if the result is close and then in dispute.
Of the half-dozen best-known pollsters in Venezuela, a majority put Chavez ahead but they also show Capriles creeping up in recent weeks, and two polls put him just ahead.
Despite two bouts of cancer since mid-2011, Chavez has declared himself completely cured and is trying to recapture his old energy to win another six-year term.
He campaigned in two states on Sunday while Capriles had his biggest turnout yet at the rally in Caracas.
Western investors hope the more business-friendly Capriles will win and end a nationalization drive and other radical policies that have polarized Venezuela like never before and made Chavez one of the world's most controversial leaders.
Chavez promises to "deepen" socialism if he wins. That would likely mean continued spending on his popular welfare "missions," more investment from politically aligned allies like China and Iran, new confrontations with Venezuela's private sector and continued support for fellow leftists governments in Latin America such as Cuba and Nicaragua.
"The first thing we are going to do with our victory is something like put a lockdown on what we have achieved, to prevent any going backwards. That would be terrible," Chavez said in an interview on state TV.
After election wins in the past, Chavez has launched nationalization or constitutional reform drives.
Opposition leaders are angry at Chavez's use of state resources in his campaign but say the electronic-based voting system should be hard to rig on election day, since they will have their own observers at most voting booths.
(Additional reporting by Helen Murphy, Girish Gupta, Marianna Parraga and Mario Naranjo)