Strikes against Houthi military targets overnight in Yemen by the UK and the US are "necessary and proportionate" to protect global shipping in the Red Sea according to Prime Minister Rishi Sunak.

Over 60 targets in 16 locations used by the Iran-backed Houthi rebels in Yemen were struck, the US Air Force said.

Sunak said, "despite the repeated warnings from the international community, the Houthis have continued to carry out attacks in the Red Sea, including against UK and US warships just this week.”

"This cannot stand. The United Kingdom will always stand up for freedom of navigation and the free flow of trade."

Sunak added that the UK had "taken limited, necessary and proportionate action in self-defence, alongside the United States with non-operational support from the Netherlands, Canada and Bahrain".

The PM said the aim of the action was "to degrade Houthi military capabilities and protect global shipping".

Houthi officials warned in response that the UK and US will “pay a heavy price”.

The attack added to concerns that the conflict in Gaza could escalate into the wider region.

The Iran-backed rebels control much of Yemen and have said they are supporting Hamas by targeting ships heading to Israel. In November they seized what they said was an Israeli cargo ship.

The rebels have launched 25 attacks on commercial vessels in the Red Sea since November, forcing the suspension of shipping through the key trade route. 

Almost 15 per cent of global sea trade passes through the Red Sea. The German economic institute found a drop of nearly two-thirds in the number of containers travelling through the Red Sea daily, from 500,000 in November to 200,000 in December.