LONDON: Britain and the United States on Thursday said they had imposed sanctions on key Houthi figures to protect maritime security in the Red Sea.

British Foreign Secretary David Cameron said the restrictions “reinforce our clear message to the Houthis in recent weeks,” promising to target those behind the “unacceptable and illegal actions” against shipping.

Four key Houthi figures involved in the attacks will be subject to UK asset freezes, arms embargoes and travel bans, a statement from Cameron’s department read.

Targets of the sanctions include the commander of the Houthi naval forces and the Houthi defence minister, both of whom are involved in co-ordinating the recent attacks on international shipping in the Red Sea, it added.

“We can degrade their ability to attack international shipping. We are determined to protect freedom of navigation. We will back our words with actions,” Cameron said.

Houthis order US, British nationals to leave Yemen

The sanctions are the first to be jointly imposed against the Iran-backed Houthis by the UK and US since the attacks began in November.

The Houthis have vowed to continue their strikes – just one part of a growing crisis in the Middle East linked to the Israel-Hamas war, which has raised tensions across the region as well as fears of a broader war directly involving Iran.

Pre-existing sanctions against 11 Houthi individuals and two entities remain in force.

“Today’s joint action with the United Kingdom demonstrates our collective action to leverage all authorities to stop these attacks,” Brian Nelson, the US Treasury Department’s for terrorism and financial intelligence, said in a statement.

The Houthi “attacks on merchant vessels and their civilian crews in the Red Sea and the Gulf of Aden have disrupted international supply chains and infringed on navigational rights and freedoms,” the US State Department said in a separate statement.

It added that the US “is committed to safeguarding international commercial trade and taking action alongside our allies and partners safeguard the safety of these critical waterways.”

US and UK forces struck Houthi targets on Monday, their second round of joint military action after a first wave of strikes against the rebel group earlier this month.

The United States has also launched individual air raids against missiles that Washington said posed imminent threats to both civilian and military vessels.

The rebels warned on Tuesday that the US-UK strikes would not go “unanswered and unpunished”.