CARACAS: A Venezuelan opposition election candidate was shot dead while campaigning, political leaders said Thursday, raising tensions ahead of a legislative vote that could weaken the major oil producer’s socialist government.

An attacker shot Luis Manuel Diaz on Wednesday evening at an event also attended by Lilian Tintori, the wife of a jailed opposition leader and a high-profile critic of President Nicolas Maduro, the official said.

“As the rally with Lilian finished, we heard shooting... We saw Luis fall to the ground bleeding,” a regional leader of the Justice First opposition party, Abrahan Fernandez, told AFP.

Another political ally of the victim, the chairman of the Democratic Action party Henry Ramos Allup, said on Twitter that Diaz was shot at short range near the stage where he had made an appearance.

He said Tintori took refuge with security guards in a nearby shop.

Polls have indicated Maduro’s government could lose its majority in the national assembly in the December 6 vote, potentially weakening the president’s grip on power.

That has raised fears of unrest in the Latin American nation of 30 million people, already wracked by violence and an economic crisis with many families short of basic supplies.

Ramos said the shooter was believed to be a member of an “armed gang” linked to the ruling United Socialist Party of Venezuela (PSUV).

Tintori’s husband Leopoldo Lopez is in prison for incitement to violence in 2014 anti-government protests, though a fugitive prosecutor in the case has cast doubt on his conviction.

That unrest left 43 people dead, according to the government.