Eight people, believed to have been victims of human trafficking, were found dead in a smugglers' truck in San Antonio, Texas on Sunday, alongside 30 now-hospitalised survivors. The local archbishop has lamented the 'senseless deaths'.

Eight people, believed to be illegal immigrants smuggled into the US, were found dead early on Sunday inside a swelteringly hot 18-wheeler truck. Another 30 adults and children, still alive, were found alongside the dead in the truck, which was parked behind a Walmart store in San Antonio. A ninth victim died in hospital.

'There are no words to convey the sadness, despair, and yes, even anger, we feel today at learning of the completely senseless deaths of nine people who died as human smuggling or trafficking victims from heat exhaustion and suffocation in San Antonio overnight,' said local Arcbishop Gustavo Garcia-Siller on Sunday, according to Catholic News Agency.

'This is an incomprehensible tragedy.'

Survivors have been hospitalised for treatment for heat-exhaustion, and 20 in 'critical to very critical' conditions were airlifted to seven different hospitals. The truck lacked any air conditioning or a water-supply. Garcia-Siller added: 'We pray for these victims and all victims of human smuggling and trafficking; that this monstrous form of modern slavery will come to a quick and final end.

'God cries seeing this reality and many other situations such as this across our country and around the world.'

The victims were reportedly found when someone from the truck went into the Walmart to ask for water, prompting staff to call the police.

The truck driver was arrested and will be charged, said Richard Durbin, US Attorney for the Western District of Texas. He said in a statement: 'These people were helpless in the hands of their transporters...Imagine their suffering, trapped in a stifling trailer in 100-plus degree heat.

The trafficked were victims of 'ruthless human smugglers indifferent to the well-being of their fragile cargo,' he said.

The archbishop said the tragedy was a 'clarion call' for all levels of society to work towards combatting and eradicating human trafficking.

'No more delays! No more victims!' he said.

Additional reporting by Reuters