The Government is considering strikes on targets in Yemen in a bid to stop attacks by Iranian-backed Houthi rebels on ships in the Red Sea.
Prime Minister Rishi Sunak held an emergency cabinet meeting on Thursday night as the situation appeared to escalate.
A British warship joined three US ships and a French vessel last month in a bid to protect the ships in narrow strip of water between Yemen and east Africa, which is a key trade route, but the attacks have continued.
Here, the PA news agency looks at what ships have been deployed and which others may be sent there following Thursday night’s developments.
– HMS Diamond
The warship has joined a US-led taskforce called Operation Prosperity Guardian which aims to ensure the Red Sea remains safe for passing ships.
Defence Secretary Grant Shapps said on Wednesday the vessel “successfully repelled the largest attack from the Iranian-backed Houthis in the Red Sea to date”.
He added: “Deploying Sea Viper missiles and guns, Diamond destroyed multiple attack drones heading for her and commercial shipping in the area, with no injuries or damage sustained to Diamond or her crew.”
According to the Ministry of Defence, the vessel’s main role is to protect other ships with air defence using its Sea Viper anti-air missile system and it can detect enemy threats “at range”.
It is nearly as tall as Nelson’s Column but designed to be “virtually impossible” for the enemy to see.
The vessel is said to have “cutting-edge military sensors” and “a range of sophisticated weapons systems” which make it “ready to detect and destroy any airborne, surface and sub surface threat”.
Ships with its name have existed for more than 400 years and there have been at least 14 in total.
– HMS Richmond
The ship was the second British one deployed to the Red Sea and was dispatched there on Tuesday.
The Defence Secretary said on Twitter/X: “HMS Richmond is on its way to the Red Sea to ensure the UK maintains a formidable presence in the face of attacks by the Iranian-backed Houthis.”
He told MPs the vessel was being deployed to replace British ones already patrolling the Red Sea as he sought to play down claims the crisis had escalated.
The type 23 frigate was designed to hunt for enemy submarines but since the end of the Cold War its role has become more varied.
It now undertakes “virtually every type of operation imaginable” from counter-narcotics and anti-piracy to disrupting people trafficking and detaining criminals.
The first ship to carry its name was launched in 1655 and took part in the Anglo-Dutch wars.
– HMS Lancaster
The vessel has been deployed in the Gulf of Oman near the Iranian mainland.
The US Combined Maritime Forces posted on X on Monday that 11 million dollars worth of illegal drugs were seized from a vessel by crews from a US ship and HMS Lancaster earlier this month.
The vessel performs a variety of roles from drug-busting operations to protecting international shipping lanes.
It can deploy with a Wildcat maritime attack helicopter, which the Ministry of Defence says makes it “ideal for our most challenging defence engagement and security operations”.
The first HMS Lancaster was built in 1640 and took part in the siege of Louisbourg, Canada.
– US warships
American destroyers USS Gravely, USS Laboon and USS Mason have all been deployed in the Red Sea, and are supported by aircraft carrier USS Dwight D Eisenhower.