An anti-government strike paralyzed large sections of Venezuela on Thursday as the nation risked spiraling into a deeper crisis ahead of a vote that many fear could move the country further down the path of authoritarian rule.

President Nicolás Maduro played down the strike, and some areas in the capital and elsewhere appeared less affected. But in many districts, a significant number of businesses were shuttered and protesters blocked roads as the opposition sought to stage Venezuela’s largest general strike since 2002. 

In Caracas, the strike was most pronounced in the eastern neighborhoods, a middle- and upper-middle-class bastion.

In the neighborhood of Los Ruices, national guard forces fired tear gas at protesters near the headquarters of the pro-government TV station Venezolana de Televisión. Demonstrators hurled back canisters. Maduro accused the mayor of the area, Carlos Ocariz, of organizing “the attack” and ordered the capture of “terrorists” striking in the area.

Similar confrontations reportedly occurred in other parts of Caracas and in other cities.

We put up the barricade early, around 5 a.m. . . . The objective is that no one goes to work, that people stay home for 24 hours,” said Caracas resident Edmond Fakrhi, 55. “We want liberty. We want democracy. We want everyone to have access to food.”

Alfredo Romero, co-director of Foro Penal, a human rights group that defends political prisoners, tweeted that at least 261 protesters were arrested as of 9:30 p.m. Thursday.

The attorney general’s office confirmed two deaths in the unrest, a 24-year-old man in Los Teques, about 20 miles southwest of Caracas, and a 23-year-old man in Valencia, 81 miles west of Caracas. The deaths brought the number of fatalities in more than three months of street protests to 94.

The opposition effort unfolded as Maduro’s unpopular socialist government faced escalating international pressure to back off the special election on July 30. The vote would elect a body to rewrite the 1999 constitution and further squelch the opposition-controlled National Assembly in a move widely viewed by critics as a power grab.

The Trump administration, pressed by prominent U.S. lawmakers, is weighing sanctions up to and including bans on Venezuela’s all-important oil exports if the vote is not called off. In an official report, Luis Almagro, secretary general of the Organization of American States, said Wednesday that there are fears that the situation in Venezuela “will escalate into a bloodbath.”

“The reluctance of the international community to act in defense of democracy has allowed the situation to deteriorate incrementally but consistently, to the point where today it has become a full-blown humanitarian and security crisis,” Almagro later said at a U.S. Senate hearing. “Every step of the way it has been too little and too late.”

Pressure was building inside Venezuela, too. The last time the opposition called for a general strike was in October, but that effort did not elicit the widespread street closures seen Thursday. In 2002, a prolonged national strike failed to oust President Hugo Chávez, who died in 2013 and had anointed Maduro as his successor. 

Unlike the wide popularity enjoyed by Chávez, support for Maduro is fast eroding amid food and medical shortages and runaway inflation. On Sunday, the opposition carried out an unofficial referendum in which more than 7 million voters rejected the government’s bid to draw up a new ­constitution and demanded new national elections. This week, the opposition pledged to form a transitional government as part of its effort to force new elections.  

Venezuela, meanwhile, suffered a diplomatic blow Thursday when a senior member of its United Nations delegation, Isaias Arturo Medina Mejías, abruptly resigned, citing “irreconcilable differences” with the Maduro government.

On the streets of Caracas on Thursday, Alfredo, a 17-year-old who did not give his last name for fear of reprisals, put up a barricade with his friends, all around his age, at 6 a.m. 

“We’re tired,” he said. “We have to take to the streets. And people should do it even if leaders don’t do it. I’m here every day, and I’ll be here today, all day.” 

Government officials, however, remained defiant and deemed the strike a failure. “The 700 most important businesses in the country are 100 percent working,” Maduro said on national TV. “Today, work triumphed.” 

The president of the National Federation of Transportation Workers, though, called the strike “an absolute success.”  

“In Caracas, I’d say almost 90 percent of transportation isn’t functioning, the terminals are paralyzed,” said Erick Zuleta, the union leader. “Buses and cars owned by the government are working, but those affiliated to us aren’t.”

Freddy Guevara, vice-president of the opposition controlled National Assembly, said  in a press conference that about 85 percent of those called on participated in Thursday’s strike. He said it was planned to end at 6 a.m., but issued a call for a national march on Saturday.

“We want to congratulate the people for this historic day,” Guevara said.

The precise course that the Trump administration will take on Venezuela remains unclear. On Monday, President Trump called Maduro a “bad leader” and threatened “strong and swift” sanctions if the July 30 vote is not called off. People familiar with the discussions say administration hawks are at odds with officials at the State and Energy departments over just how broad those sanctions should be. 

A more narrow approach could target U.S. assets of senior Venezuelan officials. A tougher one, being backed by some in the administration and influential Republicans, could hit Venezuela where it hurts — the oil industry. 

A third of the country’s 2.1 million barrels a day is exported to the United States, mostly for refining at facilities in Texas and Louisiana . Oil sanctions could range from limiting the industry’s access to U.S. financial markets to outright bans on imports and re-exports.

Yet Venezuela relies on its oil trade with the United States to finance food and medicine imports, meaning that sanctions are likely to further hit the long-suffering Venezuelan people and potentially fuel anti-American sentiment. They could also cause supply-chain problems in the United States, at least temporarily raising gas prices slightly.

But the resulting pressure on the Venezuelan government, some argue, could be a powerful tool at a critical time. 

“Trump always criticized [President Barack] Obama for threatening and not doing anything,” said Francisco J. Monaldi, a fellow at the Baker Institute for Public Policy at Rice University. “Just two months ago, I would tell you it’s not going to happen. But I’m hearing from the oil companies that they are all preparing for it.” 

Faiola reported from Miami.