CUCUTA, Colombia – Thousands of Venezuelans are pouring out of their crippled nation in one of the biggest migration crises in Latin American history, causing growing alarm in the region and prompting neighboring countries to rush thousands of soldiers to the border.

The massive scale of the exodus is being compared to the flow of Syrians into Western Europe in 2015. And, just as in that crisis, countries overwhelmed by the flood of new arrivals are beginning to bar their doors.

"This is a humanitarian crisis," said Willington Munoz Sierra, regional director of the Scalabrini International Migration Network, a Catholic charity running a shelter in this border city, where desperate Venezuelans are now living in parks and cheap motels or sleeping on sidewalks. "In Venezuela, children are dying. People are starving and being persecuted. What they're getting from us is a door in the face."

Nowhere is the crisis more acute than here in Colombia, where 3,000 troops are fanning out across the 1,400-mile border to contain an influx of Venezuelans fleeing a collapsing economy and an increasingly repressive socialist regime. Roughly 250,000 Venezuelan migrants have surged into Colombia since August, with 3,000 a day still arriving.

The sheer numbers have led to a backlash in Colombian cities and towns, prompting the national government last month to suspend the issuance of temporary visas for Venezuelans. Colombian authorities are now launching operations in which dozens of Venezuelans a day are captured and expelled.

"Let's go!" Maj. Jarlinzont Zea barked into his walkie-talkie one recent afternoon, jumping out of a police truck in this city of 650,000. Simultaneously, dozens of Colombian officers and migration officials poured out of vehicles and stormed a park, sending panicked Venezuelans scattering.

One slight young woman, in a black tank top and denim shorts, didn't move fast enough.

"What's your name?" an officer demanded.

"Andie," she said, quaking.

"Papers," insisted the officer.

"I don't have any."

"Where are you from?"

"Venezuela," she said, near tears. "Please. I — can't. I can't go back."

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Latin America has seen mass exoduses before. In the decades after Fidel Castro's 1959 revolution, about 1.4 million Cubans fled the island, many heading for the United States, where they transformed the social and ethnic fabric of Miami. During the 1980s and 1990s, more than 1 million people — more than a quarter of the population — were displaced during El Salvador's civil war.

Yet there is little precedent in the region for the speed and intensity of the Venezuelan migrant crisis.

After the leftist firebrand Hugo Chávez became president in 1999, thousands of Venezuelans — especially from the upper classes — moved out of the country. But the current exodus is far more dramatic.

Under Chavez's hand-picked successor, President Nicolás Maduro, Venezuela has reached a breaking point, with lower oil prices and economic mismanagement leading to the world's highest inflation rate and spiraling indexes of poverty and malnutrition. At the same time, Maduro's government has jailed and allegedly tortured opponents, sparking a wave of political asylum-seekers.

Nearly a million Venezuelans have left their country over the past two years, according to the International Organization for Migration, with experts citing a surge during the second half of 2017, when the economy took a sharp turn for the worse. That figure is in addition to the hundreds of thousands who departed between 1999 and 2015.

"Our migration levels are now comparable to Syria or to [the Rohingya going to] Bangladesh," said Tomás Páez, an immigration expert at the Central University of Venezuela. More than a million Syrians, Afghans, Iraqis and others fleeing war and poverty poured into Europe in 2015, and 650,000 Rohingya Muslims have recently fled persecution in Myanmar, seeking refuge in Bangladesh.

Globally, the growing Venezuelan diaspora is reshaping cities from Miami to Buenos Aires to Madrid. But most Venezuelan migrants are staying in Latin America, where countries are handling a dire situation in different ways.

In Brazil, President Michel Temer declared a state of emergency after a visit to his country's border with Venezuela last month and pledged $20 million plus a new field hospital to ease the crisis. Four shelters on Brazil's southern border are now packed with Venezuelans, officials say, with an estimated 40,000 additional Venezuelan migrants residing in Boa Vista, the closest big Brazilian city to the border.

Officials say they will treat the newcomers as Brazilian citizens. But Temer also vowed to double the number of troops at the border.

Peru is offering temporary resident permits to Venezuelans, granting them the right to work. Last year, nearly 149,000 Venezuelans entered the country, up from 40,000 in 2016, according to Peruvian government statistics.

"We're going to Peru because I cannot feed my children in Venezuela," said Liuiben De Navarro, a 28-year-old seamstress who, on a recent morning, crossed the Colombia border at dawn with her two young children.

She and a host of other Venezuelans — army deserters, laborers, nurses — arrived to a barrage of offers from touts peddling trips on rickety buses to cities such as Quito, Lima and Santiago. A few feet away, desperate Venezuelans sold scrap metal to Colombian junk merchants.

"I love my country," De Navarro said. "But we cannot get food."

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On a recent morning in Cucuta, the scene resembled a refugee crisis, with women clutching babies and exhausted families toting old suitcases streaming across a border bridge. The most desperate headed straight to the hospital.

"We don't know where to turn," said Jose Urriola, 30, standing next to his 18-month-old daughter, Mavis, who languished in a hospital bed. The family had recently arrived from Venezuela. The little girl was malnourished and also had developed a life-threatening heart blockage. The hospital was petitioning national authorities for funds before proceeding with the costly operation.

Winston Martínez, deputy director of Colombia's migration agency, said the country was not conducting "mass deportations." Instead, he said, it was carrying out special operations designed to limit the number of Venezuelans without valid visas. He noted that the government is offering Venezuelans who have passports the chance to apply for special resident visas and has already awarded more than 160,000.

Shortly after Andie, the woman in the black shirt and jean shorts, was detained by police, they loaded her onto a truck. About 15 minutes later, she and three dozen other migrants were released at a border bridge.

One by one, the migrants walked back toward Venezuela as the Colombian officers watched.

And then only Andie was left.

"You have to go," said a female officer.

"I can't," Andie said, her voice breaking. "Please. I'm pregnant, and we won't survive there."

The officer paused. "I'm sorry, honey, but you need to go back."

Andie nodded, then turned. Sobbing, she walked across the bridge.