AFP/GEORGE CASTELLANOS People wait outside the customs office in San Antonio del Tachira, Venezuela, for the opening of the passage to the Simon Bolivar international bridge, which links the city with Cucuta, in Norte de Santander province, Colombia, on Dec. 20, 2016.

On the Colombia-Venezuela border, Joe Parkin Daniels reports on the increasing numbers of people fleeing both ways over the frequently closed border to escape humanitarian problems in each of the countries.

BOGOTA, COLOMBIA – A migrant crisis is simmering on the Colombia-Venezuela border, as Colombians flee continuing violence and Venezuelans seek refuge from unrest and economic collapse in their country.

Although the border is often closed amid tensions between the two countries, people are increasingly traveling in both directions to escape humanitarian problems in their respective countries.

In Colombia, a peace deal ratified last November with South America’s oldest leftist rebel group, the Revolutionary Armed Forces of Colombia (FARC) has opened a vacuum in the vast criminal economies – including drug trafficking and illegal mining – that the rebels relied on to fund their war effort.

While many Colombians are celebrating the formal end to 52 years of war that left at least 220,000 dead and nearly 7 million displaced, those living in areas of former FARC control live in fear of emergent armed groups contesting the guerrillas’ illegal trafficking routes.

In early February, U.N. officials said that armed groups displaced 96 families in the hotly contested Norte de Santander region, a hub for coca cultivation and illegal mining on the border with Venezuela. Some crossed into Venezuela, while others remained in Colombia, seeking refuge in nearby towns, the U.N. said.

While Colombia’s foreign minister Maria Angela Holguin said there was “no certainty of any such displacement,” the Venezuelan government, led by President Nicolas Maduro, said that 359 displaced Colombians had arrived at the border since the peace deal passed. UNHCR said in February that 200 people from the region are receiving humanitarian aid in Venezuela.

Chief among the groups responsible for displacement along the border are descendants of the United Self-Defense Forces of Colombia (AUC), a paramilitary federation with ties to landed elites that demobilized in 2006. That demobilization was widely denounced as ineffective, as many fighters did not turn in their weapons.

Referred to by the government as Bacrim (from the Spanish for criminal gangs), these groups have been violently staking their claim to the FARC’s former territory. In December, the office of the U.N. High Commissioner for Human Rights in Colombia said that the government must do more to protect rural citizens from such armed groups.

UNHCR said that some 173,673 Colombians living in Venezuela were seeking international protection at the end of 2016. Another 8,500 are recognized refugees.

Crisis in Venezuela

Yet, migration across the border is not just one-way.

Venezuela, the country with largest proven oil reserves on the planet, is currently in economic tailspin. The Financial Times reported that inflation could reach 1,600 percent this year. The country’s over-reliance on oil amid falling global prices and its hermetic foreign policy have caused many Venezuelans to live in a state of constant despair.

Amid shortages in basic goods, from tinned food and toilet paper to medication, people line up for hours in the vain hope they can buy food for the day, often with backpacks stuffed with almost-valueless Bolivar currency notes. The black market for household goods is booming, but at exorbitant prices the average Venezuelan cannot afford. Many Venezuelans try to travel to Colombia where the shelves are full.

In the past year, there has been an influx of Venezuelans into Cucuta, the capital of Colombia’s Norte de Santander region where paramilitary successor groups are expanding. During one border opening last July, some 120,000 people crossed the border to buy basic goods and receive medical treatment.

Last December, the Miami Herald reported on one woman who was eight-months pregnant, crossing into Colombia to give birth to twins amid a wave of migration. “I had no choice,” Marili Gomez told the newspaper. “I wanted my babies to live.”

It is hard to precisely estimate the number of Venezuelans who have sought refuge in Colombia, but the U.N. said there were more than 46,600 Venezuelans in Colombia in 2015, during the early days of anti-government protests that are still underway.

Border Closures

After years of poor relations between Colombia and Venezuela, the border between the countries is frequently closed. Venezuela sent tanks and troops to the Colombian border in 2008, after a Colombian operation to take out a FARC commander on Ecuadorian soil sparked a regional crisis. In mid-2015, thousands of Colombians were deported from Venezuela, when Maduro accused Colombia of supporting trafficking across the border.

Although tensions have since subsided, the border is still often shut, leading desperate Venezuelans and Colombians to cross illegally in both directions.

Many Venezuelans settle in Cucata without documentation and work informally in construction or housework. Some also turn to the booming illegal trade of smuggling gasoline across the border, which is state-subsidized in Venezuela but expensive in Colombia.

“The gangs bring the barrels over, we buy them and then sell them on,” said one man in Norte de Santander, who asked to remain anonymous, pointing to a jerry-rigged pump fashioned from a household funnel and plastic tubing. “We also sell gas to go, in Coca-Cola bottles. Over there [in Venezuela], gas is cheaper than water, so this is the only business that makes sense.”

Meanwhile, humanitarian organizations working with refugees and migrants often face obstruction from the opaque Venezuelan government.

The lack of refugee data from Venezuelan authorities exacerbates the difficulties of addressing the waves of migration, according to an aid worker who works on the Venezuela-Colombia border. The lack of data makes it virtually impossible to determine who is a refugee and who is an economic migrant, he said.

But in any case, both migrants and refugees face very similar situations on the Colombia-Venezuela border, the aid worker noted. Whether fleeing violence or economic turmoil, they are seeking refuge from a situation spiraling beyond their control.

This article originally appeared on Refugees Deeply. For weekly updates and analysis about refugee issues, you can sign up to the Refugees Deeply email list.