At least 46 people were found dead inside a tractor-trailer in a presumed migrant smuggling attempt in South Texas. “These deaths are on (Joe) Biden”, Texas governor Gregg Abbott wrote in a social media post on Monday.

“They are a result of his deadly open border policies. They show the deadly consequences of his refusal to enforce the law”, Abbott wrote shortly after the incident was reported.

Also Read: US officials arrests over 200,000 migrants crossing Mexico border in March

US President Joe Biden, a Democrat, has largely reversed all migration policies set by his predecessor Donald Trump, a Republican. These include boosting refugee admissions, preserving deportation relief for unauthorised immigrants and adopting lenient border policies.

Immigration has been a partisan issue for lawmakers in the US Congress. Most Republicans from southern-US states rally for stricter border policies, while Democrats support regulated borders.

The recent 46 deaths were reported in Texas’ San Antonio and unnamed officials told Associated Press that there were at least 15 others in the truck, who have now been taken to nearby hospitals.

It may be the deadliest tragedy among thousands who have died attempting to cross the US border from Mexico in recent decades. Ten migrants died in 2017 after being trapped inside a truck that was parked at a Walmart in San Antonio. In 2003, 19 migrants were found in a sweltering truck southeast of San Antonio.

Also Read: Is Washington DC being stingy with Ukrainian refugees?

Big rigs emerged as a popular smuggling method in the early 1990s amid a surge in US border enforcement in San Diego and El Paso, Texas, which were then the busiest corridors for illegal crossings, according to Associated Press reports.

Heat poses a serious danger, particularly when temperatures can rise severely inside vehicles. Weather in the San Antonio area was mostly cloudy Monday, but temperatures approached 100 degrees.