The number of deaths rose to 53 in a tractor-trailer tragedy in the US state of Texas after two more migrants died, according to the US Immigration and Customs Enforcement on Wednesday.

Eleven remain hospitalized, Tanya Roman, spokesperson for the Office of Public Affairs, told Anadolu Agency.

"The victims identified at this time are from Mexico, Guatemala, and Honduras," said Roman. "Information on the remaining survivors will be provided when available".

Authorities found nearly 40 deceased migrants inside the back of the truck in San Antonio amid high temperatures Monday. They said the victims suffered heat-related illnesses.

Homeland Security Investigations has launched an investigation with the support of the San Antonio Police Department into the tragedy.

Police said temperatures in southcentral Texas hit 103 degrees Fahrenheit (39.4 degrees Celsius) when the bodies were discovered.

The new figure was first confirmed by officials to The Washington Post and a local television station.

President Joe Biden described the deaths as “horrifying and heartbreaking,” and said the tragedy "underscores the need to go after the multi-billion dollar criminal smuggling industry preying on migrants and leading to far too many innocent deaths."/aa