A five-year-old boy saved his younger brother, a two-year-old toddler, from the burning wreckage of an accident that killed their father, US media reports said.

The father was driving an 18-wheeler trailer, which crashed into a guardrail and metal pillar on a highway on Friday (Oct 14) in Houston, Texas, the New York Daily News reported.

The truck tipped over and the cabin burst into flames, but the five-year-old boy, who has not been named, told police officers that he pulled his younger brother out of the fire.

Their father died at the scene.

"The 5-year-old actually advised us that he pulled his 2-year-old little brother out from the 18-wheeler wreckage," a police officer told TV news channels.

"He's a trooper, he was ejected and he was sitting down and talking to us... he helped us out a lot to piece together a lot of things."

The boy told police that the family was moving to Galveston, Texas, and his mother was driving ahead of them in a different vehicle.

Daval Shah, a hotel manager who saw the crash, said he saw the two-year-old lying on the road. He "grabbed" both boys and waited for police to arrive, said a KPRC news report.

The older boy suffered minor injuries, while his brother has sustained some "severe burns". Both are expected to recover.