Four men were indicted by a grand jury in Texas on Wednesday after the deaths of 53 migrants who were found abandoned in late June in an overheated tractor-trailer in San Antonio.

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Two Texans, Homero Zamorano, 46, and Christian Martínez, 28, have been charged with criminal association for the transport of migrants that led to their death, the Justice Department said in a statement.

They face the death penalty.

The jury also indicted two Mexican nationals, Juan Claudio D'Luna-Mendez and Juan Francisco D'Luna-Bilbao, on counts of illegally carrying weapons and unlawful presence on US soil.

These two individuals lived at the address associated with the license plate of the truck, explained the ministry. They face up to 10 years in prison.

The four men were arrested shortly after the discovery of the mass grave, where 46 victims had already died.

Homero Zamorano, identified as the driver of the truck, was arrested at the scene, "hiding in the thickets after trying to escape," the federal prosecutor in charge of the case said three days after the tragedy.

A San Antonio city worker heard a call for help on June 27 near a road where he worked. He then discovered an abandoned truck in the trailer of which were 64 migrants, 46 of whom had already died. Seven others died of their wounds.

Temperatures had hovered around 40 degrees on the day of the macabre discovery, and the survivors were suffering from hyperthermia and acute dehydration.