Mexico’s Foreign Minister Marcelo Ebrard called the suffocation of the migrants in the truck the “tragedy in Texas” on Twitter and said the local consulate was en route to the scene, though the nationalities of the victims had not been confirmed.

There have been a record number of migrant crossings at the US-Mexico border in recent months, which has sparked criticisms of the immigration policies of US President Joe Biden, a Democrat.

Temperatures in San Antonio, which is about 160 miles (250 km) from the Mexican border, swelled to a high of 103 degrees Fahrenheit (39.4 degrees Celsius) on Monday with high humidity.

In July 2017, ten migrants died after being transported in a tractor-trailer that was discovered by San Antonio police in a Wal-Mart parking lot. The driver, James Matthew Bradley, Jr., was sentenced the following year to life in prison for his role in the smuggling operation.More than 40 migrants die in truck in San Antonio, others hospitalized