South African billionaire Elon Musk has claimed to have sold $5m (£3.5m) of flamethrowers through his Boring Company since the weekend.

The tech entrepreneur, who also founded the electric car company Tesla, promised to begin selling the devices if the Boring Company could shift 50,000 baseball caps at $20 (£15) each.

The flame thrower costs $500, and the billionaire has taken to Twitter to suggest he has shifted 10,000.

Mr Musk first tweeted about the flame throwers on Sunday, telling one of his followers that they offer “max fun for least danger. I’d be way more scared of a steak knife.”