The firearms include Kalashnikovs, pistols, grenades, and grenade-launchers, with dealers operate in areas controlled by the Houthis – a rebel group backed by Iran and classified as a terrorist organisation by the US and Australian governments.

Edmund Fitton-Brown, a former British Ambassador to Yemen who now works for the Counter Extremism Project, told the BBC: “It is inconceivable that they (the weapons dealers) are not operating on the Houthis’ behalf.

“Purely private dealers who tried to profit from supplying, (for example) the government of Yemen, would be quickly shut down.”

A recent investigation by The Times uncovered how a string of Yemeni accounts engaged in this trade bore the blue tick of verification on X, a feature that supposedly indicates authenticity.

Despite approaches from both The Times and the BBC, Elon Musk’s X has yet to comment on the situation.

It comes after content moderators were laid off following the billionaire’s acquisition of the company in 2022.

The advertisements, which were primarily in Arabic, are targeted at Yemeni customers in a country where guns are said to outnumber the population by three to one.

A BBC report said it had found numerous examples of online posts offering weapons, with one ad proclaiming: “Premium craftsmanship and top-notch warranty.”

Another video shows a seller firing a 30-round magazine on full automatic, while another post offers sand-colored Pakistani-made Glock pistols for around $900 each.

The transactions are not hidden on the Dark Web but are in plain sight, easily accessible to millions.

UK-based NGO Tech Against Terrorism has issued an urgent plea to tech platforms to remove Houthi-supporting content, highlighting the growing concern over the group's expanding influence.