Thousands of union members and anti-government protesters took to the streets of Colombia on Thursday for a 12-hour nationwide strike, making the Andean nation the latest in South America to break out in large-scale civil unrest.

The protesters, who waved flags and banners, represented a range of disgruntled sectors of society — students, unions, and leftist and indigenous groups — that share rising anger against the increasingly unpopular government of conservative President Iván Duque.

In Bogota, the capital, protesters waved the flags of Chile and Ecuador and carried banners that read “South America woke up” and chanted “without violence.” Videos circulating on social media showed riot police firing tear gas and apprehending demonstrators.

Initially called by unions, the strike grew as other sectors joined in, furious over labor, pension and tax reforms being discussed in the national Congress, the killings of community organizers and indigenous leaders, and general dissatisfaction with the government’s failure to fully implement the historic 2016 peace accord with the guerrillas of the Revolutionary Armed Forces of Colombia, or FARC.

The government closed Colombia’s borders and deployed 170,000 members of the security forces, the Associated Press reported. In the days before the strike, police raided homes of artists and activists who they claimed were preparing to unleash violence Thursday.

Earlier, the government deported 24 Venezuelan nationals accused of instigating unrest. Duque views Venezuelan President Nicolás Maduro as an adversary intent on fomenting trouble in Colombia. But demonstrators insisted their anger was homegrown. They blocked roads in Bogota and caused the partial suspension of subway operations in Medellin and Cali. Schools and businesses in the three largest cities were closed.

Authorities said demonstrators sprayed graffiti and broke windows of public buses and subway stations in Cali, pulled down traffic lights and attacked an ambulance. Police fired tear gas in Cali and Cartagena, leading to the cancellation of an infrastructure conference. The mayor of Cali declared a curfew at 7 p.m.

“This is a peaceful protest to tell the government we are against the labor and pension reforms, calling the government to meet their promises to students and workers,” Víctor Correa, a former mayoral candidate in Medellin, told the national newspaper El Tiempo. “We also call for peace, for a good government, and against a government that has been regressive and that has fragmented the country.”

Protests have broken out in Chile, Bolivia, Ecuador and other South American nations in recent months, each with its own set of grievances. The largest have been in Chile, where outrage over a transit fare hike snowballed into rage over inequality, and in Bolivia, where political polarization over the ousting of Evo Morales as president has fueled days of deadly clashes.

The unrest in those countries has continued in part because protests have won concessions. Chilean President Sebastián Piñera has rolled back a subway fare increase and other austerity measures; Bolivia’s Morales resigned the presidency and fled the country.

Whether the strike in Colombia on Thursday will grow into a similarly sustained wave of protest is unclear. In a televised address Wednesday, Duque said his is a “government that listens” — but also suggested that the grievances stem from previous governments or are based on misinformation.

“We know that there are many challenges that we as a country have to overcome,” he said. “That many of the social aspirations are valid and that we have problems that throughout history have aged in a bad way.

“Yet there are many that see this protest as an opportunity to spur agitation based on lies, to generate divisions,” he said.

Earlier in the week, Duque said protest organizers were spreading fake news about his government’s supposedly intending to raise the age for pensions and reduce wages for young workers. He said that his government had not drafted any pension or labor reforms and that his intention was to discuss the measures with civil society groups.

Protesters were concerned by proposals presented in Congress by former president Álvaro Uribe, Colombian media outlets reported. Uribe leads Duque’s political party and is seen as a close ally.

Students have been protesting intermittently for about a year for more resources for public education. In September, students in Bogota vandalized buses and confronted the police.

Duque, whose popularity has fallen to 30 percent in the latest Gallup poll, is accused of failing to fully implement the peace deal signed in 2016 by then-President Juan Manuel Santos and the FARC to end Colombia’s civil war after 50 years of strife. Dissident guerrillas and other armed groups continue to fight in the nation’s rural conflict zones. Five indigenous leaders were killed in the southern province of Cauca in October; more than 700 community organizers and indigenous leaders have been killed since 2016.

Duque is dealing with other controversies. Defense minister Guillermo Botero resigned this month after evidence emerged that children had died in operations against dissident FARC groups. Duque had called the operations “impeccable,” and the children’s deaths had been kept a secret.

Internal rifts were made public when audio of a conversation between the Colombian ambassador to the United States and the new foreign minister was leaked by the local news site Publimetro. Ambassador Francisco Santos was heard telling Foreign Minister Claudia Blum that her predecessor, Carlos Holmes, “didn’t do anything,” “had no strategy” and “was a disaster.” Holmes is now defense minister.

Santos also suggested “covert actions” in Venezuela to “generate noise and support the opposition.” He called previous Colombian strategy on Venezuela a “total fiasco.”