The Starship 36 suffered “catastrophic failure and exploded” at the Starbase launch facility shortly after 11pm (0400 GMT Thursday), a Facebook post by the Cameron County authorities said.

Musk’s Space X said the rocket was preparing for the tenth flight test when it “experienced a major anomaly while on a test stand at Starbase”.

“A safety clear area around the site was maintained throughout the operation and all personnel are safe and accounted for,” Space X added on social media.

“There are no hazards to residents in surrounding communities, and we ask that individuals do not attempt to approach the area while safing operations continue.”

Starbase on the south Texas coast, near the border with Mexico, is the headquarters for Musk’s space project.

Standing 403 feet (123m) tall, Starship is the world’s largest and most powerful rocket and central to Musk’s long-term vision of colonising Mars.

The latest setback follows an explosion of a prototype Starship over the Indian Ocean in late May.

The biggest and most powerful launch vehicle ever built had lifted off on May 27 from the Starbase facility, but the first-stage Super Heavy booster blew up instead of executing its planned splashdown in the Gulf of Mexico.

The previous two outings also ended poorly, with the upper stage disintegrating over the Caribbean.