Death toll in suspected Texas human smuggling case rises to nine

Nine suspected migrants were found dead on Sunday after being packed inside an overheated truck that was discovered in a Walmart parking lot in Texas, with 30 others being hospitalised in what police said appeared to be a "horrific" human trafficking crime.

Thirty people, many in critical condition and suffering from heat stoke and exhaustion, were removed from the trailer, which lacked air conditioning or a water supply, San Antonio Fire Chief Charles Hood said. Temperatures outside the vehicle topped 37.8 C.

Seventeen of those taken to hospitals after the discovery in the early morning hours in San Antonio - about a two hour drive from the Mexican border - were in critical condition, suffering from heat stroke and dehydration, authorities said.

At least 39 people were in the trailer, including one person who was later found in a nearby wooded area, federal prosecutors said in a statement.

At least two were school-age children Hood said.

City police chief William McManus told CNN that the dead were all adult men. Authorities were not releasing the victims' names or nationalities until their families were notified.

"All were victims of ruthless human smugglers indifferent to the well-being of their fragile cargo," San Antonio-based US Attorney Richard Durbin Jr said.

"These people were helpless in the hands of their transporters. Imagine their suffering, trapped in a stifling trailer in 100-plus degree heat," he said.

The truck's driver, named by the US Attorney's Office as James Mathew Bradley Jr, 60, of Clearwater, Florida, was arrested in connection with the incident, the statement said.

A criminal complaint will be filed in federal court in San Antonio on Monday, and Bradley is expected to have an initial court appearance shortly afterward, the US attorney said.