The Guatemalan police on Wednesday arrested seven people in connection with a June 2022 human smuggling operation that caused the deaths of 53 people, including children, in one of the deadliest episodes involving migrants on the southern border of the United States.

The number of casualties and the manner in which the migrants died caused widespread shock at the time, with President Biden describing the incident as “horrifying and heartbreaking.” The smugglers had locked the migrants inside a tractor-trailer that was abandoned on a remote road near San Antonio in sweltering heat and without air conditioning.

It also came at a time when the number of people attempting dangerous journeys through Central America to the southern U.S. border was rising. Many were pushed by political repression, gang violence and economic desperation, among other factors. The smuggling of migrants into the United States has became a billion-dollar business, with organized crime controlling many operations.

The number of crossings at the southern U.S. border has fallen sharply in recent months following asylum restrictions imposed by the Biden administration.

The National Civil Police of Guatemala said on Wednesday that officers had conducted an operation against a group of human smugglers called “Los Orozcos” in connection with the 2022 Texas migrant deaths. They arrested seven people, including the group’s leader, Rigoberto Ramón Miranda Orozco, also known as Don Rigo, for human trafficking, said Edwin Monroy, a police spokesman.

There was an “arrest warrant for extradition purposes” for Mr. Orozco, Mr. Monroy said. Francisco Jiménez, Guatemala’s interior minister, said in a post on X that the operation had “dismantled” Los Orozcos.

The operation against the group was conducted with the U.S. Department of Homeland Security, which did not immediately respond to a request for comment.

The Justice Department said it would hold a news conference on Thursday in San Antonio to announce “a significant arrest in the case.”

The arrests in Guatemala were the first outside the United States in this case. So far, three have pleaded guilty to charges related to the episode.

The smugglers locked at least 66 migrants, including eight children and a pregnant woman, in the tractor-trailer, according to U.S. authorities.

As temperatures reached 100 degrees Fahrenheit, the migrants “screamed and banged on the walls for help,” and some clawed at the insides of the trailer to try and escape, according to one of the indictments. The migrants had paid up to $15,000 each for their passage to the United States, the indictment said.

The dead included people from Guatemala, Mexico and Honduras.