Houston, Jun 28 (IANS): Four men from Mexico were arrested in Texas for their involvement with a human trafficking ring that left 53 migrants dead in a tractor-trailer in San Antonio one year ago, federal prosecutors said.

The arrests made on Monday increased the number of people charged in the case to six, Xinhua news agency quoted the prosecutors as saying.

The driver and another man werearrested shortly after the migrants were found.

They were charged with smuggling resulting in death and conspiracy.

According to the federal prosecutor, the four men were part of a human smuggling organisation that brought people from Guatemala, Honduras and Mexico into the US from December 2021 to June 2022.

They worked in concert, "sharing routes, guides, stash houses, trucks, trailers, and transporters in order to consolidate costs, minimize risks, and maximise profit", said the US Attorney's office.

"Human smugglers who put people's lives at risk for profit and break our laws cannot hide for long," Attorney General Merrick B. Garland said on Tuesday.

On June 27, 2022, 53 migrants, including children, were found dead in an abandoned 18-wheel trailer in San Antonio.

The victims included 27 people from Mexico, 14 from Honduras, seven from Guatemala and two from El Salvador.

Temperatures hit over 37 degrees Celsius that day, with the truck's air conditioning system malfunctioning.

This was the deadliest tragedy to claim the lives of migrants smuggled across the border from Mexico.