Eight people have been found dead inside a trailer truck in the US state of Texas.

20 others were discovered in a critical or serious condition, suffering heatstroke or dehydration, and taken to hospital.

The truck was parked outside a Walmart store in San Antonio.

The discovery was made after one of the people in the truck asked a Walmart worker for water, who then called the police.

Police Chief William McManus says: "We're looking at a human trafficking crime here... Right now we're looking at eight dead.

"There appears to be some juveniles, some adults in their 20 and 30s".

Fire Chief Charles Hood adds: "These people were in that trailer without any signs of any type of water.

"We're very fortunate that there weren't 38 of these people that were all locked inside that vehicle dead."