The first flight departed from Panama City with 29 Colombians on board, all of whom had criminal records in their home country and had been arrested after crossing the Darién Gap jungle that connects Colombia to Panama. The deportees were shackled and handcuffed and led to the plane.

More than half a million migrants crossed the Darién Gap last year, a record high, led by Venezuelan refugees and others from across the Americas and beyond.

The deportation flights are being carried out more frequently. They are part of an agreement concluded in July between US authorities and Panama’s new president, Jose Mulino, who had promised during the election campaign to end his country’s status as a transit country.

Panama’s immigration commissioner Roger Mojica told a news conference that efforts to deport migrants from countries other than Colombia, including Ecuador and India, were underway. But he noted that deporting Venezuelans would be more complicated because Panama severed diplomatic ties with Venezuela following last month’s disputed presidential election.

Marlen Piñeiro, an official with the U.S. Department of Homeland Security, said the goal of the deportation flights is simple.

“The message we are sending is very clear: Darien is no longer a route,” she said, stressing that migrants should only choose legal options to enter the United States.

U.S. authorities previously announced a $6 million budget for the flights and are training Panamanians. They said the repatriations would be carried out in accordance with Panama’s laws.

(Reporting by Elida Moreno in Panama City; additional reporting by Ted Hesson in Washington; writing by David Alire Garcia; editing by Rod Nickel)