This is what the Houthi rebels would say is a success story, the first ship they've sunk after months of targeting vessels in the Red Sea. It's clear this is one they were proud of. In a statement, they said, Yemen will continue to sink more British ships and any repercussions or other damages will be added to Britain's bill, as it is a rogue state that attacks Yemen and partners with America in sponsoring the ongoing crime against civilians in Gaza. Originally thought to be British-owned, later that became less clear. Either way, a sinking ship in one of the world's busiest waterways is a problem.

Some 15% of the world's trade and shipping goes through what's called the Babelmendab, which is this Southern area of the Red Sea, this gateway between the Horn of Africa and Yemen. The Houthis have a huge appetite for escalation in a way that probably nobody else has.

For days, the Ruby Mar had been drifting, taking on water after being attacked last month. The crew were rescued, but there are concerns among environmentalists about the fertilizer and the fuel on board.

This ship was carrying between 21,000 and 41,000 tons of ammonium nitrate fertilizer. There is a risk of what is called a localized acidification due to the fertilizer's high acidity. This can disrupt the PH balance and cause harmful effect on various species within the water color.

For months, the Iranian Bat Group have been making their mark, targeting commercial shipping in what they say is a campaign against Israel's offensive in Gaza. The UK and its allies in America have responded, but so far to little avail. The Houthis appear undeterred. Molly Malone, Sky News.