YEMEN'S Houthi rebels have warned strikes by the UK and US "will not go unpunished" after a second blitz targeted their arsenal.
Four RAF Typhoon jets unleashed laser-guided bombs to blast eight Houthi sites after rebels refused to halt attacks on ships in the Red Sea.
It came just hours after Rishi Sunak and Joe Biden warned the Iranian-backed militants they would strike Yemen again "if needed".
The Pentagon said Monday's strikes hit eight targets, including an underground bunker.
A US official told the strikes had "good impact" on targets, understood to have been in the capital Sanaa, al-Dailami military base, near the city of Taizz, and Bayda province.
US defence officials said warship and submarine-launched Tomahawk missiles and fighter jets were used to also take out Houthi missile storage sites and launchers.
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The UK's Ministry of Defence said the four RAF Typhoon jets were accompanied by two Voyager tankers and US forces, striking Houthi targets at two military sites near the Sanaa airfield.
These were reportedly Houthi missile storage sites and launchers both crucial for the group's attack and surveillance capabilities.
Defence Secretary Grant Shapps said: “Dangerous Houthi attacks on shipping in the Red Sea have continued to threaten the lives of sailors and disrupt shipping at an intolerable cost to the global economy.
"Along with our US partners, we have conducted a further round of strikes in self-defence.
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" These attacks are illegal, they are unacceptable.
Foreign Secretary David Cameron
"Aimed at degrading Houthi capabilities, this action will deal another blow to their limited stockpiles and ability to threaten global trade.
"Alongside our ongoing diplomatic efforts, we will continue to support regional stability across the Middle East, working hand in hand with our like-minded partners.”
But Houthis rebels have warned the UK and US to expect retaliation following the second blitz.
Military spokesman Yahya Saree said: "These attacks will not go unanswered and unpunished."
The strikes were another dramatic escalation in the crisis that for weeks has been threatening to ignite an all-out war across the Middle East over Israel's ongoing battle with Hamas.
This is the second blitz, after the first meticulously planned operation earlier this month.
At the time aircraft made their way from Cyprus to Yemen and back in hours, refuelling mid-air after they destroyed the targets.
But in the days that followed it was revealed about 30 per cent of Houthis' drone and missile stashes survived the attack.
Foreign Secretary David Cameron said the strikes sent the "clearest possible message".
He said: "Since we last took action 10 days ago, there have been over 12 attacks on shipping by the Houthis in the Red Sea.
"These attacks are illegal, they are unacceptable.
"What we have done again is send the clearest possible message that we will continue to degrade their ability to carry out these attacks while sending the clearest possible message that we back our words and our warnings with action."
Two US Seals died
Earlier on Monday evening the PM and President warned further “targeted military action to degrade Houthi capabilities” was on the table.
During a call with the White House, No10 said the pair “paid tribute to the British and American personnel who are currently working closely together to uphold freedom of navigation and protect lives in the Red Sea".
The Prime Minister passed on his condolences on the death of two US Navy Seals confirmed on Monday.
Mr Sunak said: “The leaders condemned the surge in violent Houthi attacks on commercial ships transiting the area and undertook to continue efforts alongside international partners to deter and disrupt those attacks.
“This includes work through the multinational Operation Prosperity Guardian, putting diplomatic pressure on Iran to cease their support of Houthi activity and, as needed, targeted military action to degrade Houthi capabilities.”
It was yesterday claimed Houthi militants were trying to get more weapons to ramp up Red Sea missile strikes.
US Intelligences said the rebel group were thought to be preparing for a strike on Western forces now.
Who are the Houthis?

THE Houthi rebels are terrorising vessels in the Red Sea and now their bases were blitzed in US and UK strikes - but who are they?
The Shia militant group, which now controls most of Yemen, spent over a decade being largely ignored by the world.
However, since the outbreak of the Israel-Gaza war they sprung from relative obscurity to hostage - turning one of the world's busiest
Why are they attacking ships?
The rebel group has been launching relentless drone and missile attacks on any ships they deem to be connected with Israel in solidarity with their ally Hamas.
The sea assaults have threatened to ignite a full-blown war in the Middle East as ripples from Israel's war in Gaza are felt across the region - with Iran suspected of stoking the chaos.
However, there have been frequent attacks on commercial vessels with little or no link to Israel - forcing global sea traffic to halt operations in the region and sending shipping prices soaring.
Houthi attacks in the Red Sea increased 50 per cent between November and December.
Their slogan is “Death to America, Death to Israel, curse the Jews and victory to Islam”.
And the rebel group's leaders have previously pledged the attacks will continue until Israel stops its devastating offensive inside Gaza.
On Thursday night, explosions rang out in Yemen and President Biden and PM Rishi Sunak struck over 60 Houthi targets.
The intel revealed the rebels have been carefully curating their plan of attack - pinpointing when the strikes would be ramped up and how they would gather the necessary weapons.
There are concerns the militants will receive even more lethal weapons from Tehran in the weeks to come.
More than 60 targets across 16 sites in Yemen were struck 11 days ago in a joint US and UK operation.
Jets, warships and submarines were used in attacks on Yemen's capital Sanaa, as well as four other regions, Sadah, Hodeidah, Taiz, and Dhamar.
Command and control centres, munition stores, launching bases, production facilities and air defence radar systems were wiped out in the attacks, the US said.
In the January 11 strikes western forces led by the UK and US obliterated 60 military targets in total under the cover of darkness, weakening the Iran-backed terror proxy in Yemen.
Laser-guided Tomahawk missiles and Paveway bombs, 1,200mph fighter jets, Reaper drones and destroyers were used alongside the RAF planes.
It was the first time strikes had been launched against the Houthis following months of brutal Red Sea attacks.
The Ministry of Defence yesterday released dramatic pictures of the RAF Typhoons used to conduct precision strikes on two key Houthi military targets.
Prime Minister Sunak said the "targeted strikes" were "limited, necessary and proportionate action in self defence".
Iran has historically backed the Houthis, providing them with all they require in terms of weapons, training and funding.
This month, US Navy Seals were able to seize one weapons shipment from Iran to the Houthis - intercepting a small boat filled with ballistic and anti-ship missiles.
Mr Shapps yesterday warned that Iran is "playing a dangerous game" in aiding the Houthi rebel attacks.
He told : “If you look at the situation throughout the region, throughout the Middle East, you've got the Iranian-backed Houthis, you've got Lebanese Hezbollah, you’ve got Hamas themselves trained by Iran."
In November, Iran-backed militia hijacked an Israeli billionaire's cargo ship which has 25 crew onboard.
It comes amid a backdrop of rising global tensions in recent weeks.
Shapps warned just last week that the UK was in a "pre-war" state as bubbling tensions in the Middle East threaten Western security.
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Meanwhile, Vladimir Putin's war in Ukraine, tensions in North Korea and the ever-present threat of China are cause for global concern.
Monday night's strikes are the first time the UK has led an operation like it - taking an active step in stamping out the Iran-backed Houthi threat.