CNN –
The US and Britain carried out further strikes against Houthi targets in Yemen on Monday, according to a joint statement. This marked the U.S. military's eighth round of attacks on rebel infrastructure in just over ten days.
Eight sites were attacked, according to the United States and Britain, which carried out the attacks, as well as Canada, the Netherlands, Bahrain and Australia, which supported the attacks.
Recent attacks on Houthi targets in Yemen have been “successful,” destroying missiles, weapons caches and drone systems, according to a senior military official and a senior defense official.
The officials, who briefed reporters after the operation on Monday afternoon, said the attacks had “achieved the desired effect.”
This was a smaller number than the first joint operation on January 11, in which over 30 Houthi targets were struck. Monday's attacks targeted an underground Houthi camp and sites linked to Houthi missile and air surveillance, the statement added.
The U.S. used fighter jets from the USS Dwight D. Eisenhower as well as surface ships and a submarine to attack eight locations, the senior military official said. In total, about 25 to 30 precision-guided munitions were fired at the targets, including Tomahawk cruise missiles, the official said.
The White House said earlier in the day that President Joe Biden spoke with his British counterpart, British Prime Minister Rishi Sunak, on Monday about a range of topics, including security in the Red Sea.
“Our goal remains to de-escalate tensions and restore stability in the Red Sea, but let us reiterate our warning to the Houthi leadership: We will not hesitate to defend lives and the free flow of commerce in one of the world's most critical waterways. “In the face of ongoing threats,” the countries said in their statement.
For the first time, the US also attacked an underground camp used by the Houthis, the official said. The deposit was found to have “more advanced conventional weapons,” including missiles and disposable attack drones.
Grant Shapps, the British defense secretary, said four British Typhoon fighter jets were involved in the attacks on Houthi targets. He warned that ongoing Houthi attacks on merchant vessels “endanger the lives of sailors and disrupt shipping, inflicting unsustainable costs on the global economy.”
After the latest round of US and British airstrikes in Yemen on Monday, Houthi leader Mohamed Ali al-Houthi said the attacks would only strengthen the Yemeni people.
“Your attacks will only make the Yemeni people stronger and more determined to oppose you, as you are the aggressors against our country,” he said in a statement published on X.
CNN reported on Monday that the U.S. has named the ongoing operation to target Houthi assets in Yemen “Operation Poseidon Archer,” suggesting a more organized and potentially long-term approach to operations in Yemen aimed at countering the attacks by Iran to deter the supported group by attacking merchant ships in the Red Sea.
The US has struck Houthi targets in Yemen eight times since January 11, most of which were carried out unilaterally by the US military. The first wave of attacks, in which the US and Britain hit about 30 sites in Houthi-controlled Yemen, marked the start of Operation Poseidon Archer, an official said.
The strikes targeted the Houthis' disposable attack drones, anti-ship cruise missiles and anti-ship cruise missiles, as the US sought to disrupt the group's ability to fire on international shipping lanes.
To avoid escalation, the officials said the latest attacks specifically targeted Houthi weapons and support capabilities used to attack international shipping routes, describing them as similar to the coalition's first round of attacks against Houthi targets on January 11.
“We are not currently expanding beyond this target,” the senior military official said.
Pentagon deputy press secretary Sabrina Singh said Monday that the Houthis had not launched a new attack on commercial shipping since Jan. 18. The Houthis claimed on Monday that they had attacked a US cargo ship, the M/V Ocean Jazz, but a defense official told CNN that the claim was untrue.
U.S. officials say Iran has quietly pushed ahead with the attacks, enabling and supporting its proxy groups across the region. Tehran has provided the Houthis with tactical intelligence and weapons to help them attack ships in the Red Sea, CNN previously reported. Iran continues to supply its proxy groups in Iraq and Syria, where U.S. and coalition forces have been attacked more than 150 times since October 17.
On Saturday, Iranian proxy militias launched one of their largest ballistic missile attacks since October on al-Asad air base in Iraq, leaving two U.S. soldiers suffering traumatic brain injuries, Singh said Monday.
Biden acknowledged Thursday that U.S. strikes failed to stop the Houthis, who continued to target and in some cases hit U.S. commercial vessels operating off the coast of Yemen.
But Biden said US airstrikes would continue anyway. And Singh said Monday that it will ultimately be up to the Houthis and Iranian proxy groups when they end their attacks.
Singh said last week that the Pentagon's initial assessment was that the strikes against the Houthis had been “very successful” and had destroyed “pretty much all the targets we hit,” leaving one less missile or capability left which the Houthis could then use in the Red Sea.
The Houthis have said they will not stop their attacks until the war between Israel and Hamas in the Gaza Strip ends. Houthi leader Abdul Malek al-Houthi said in a speech on Thursday that it was “a great honor and a blessing to face America head-on.”
Last week, the U.S. Navy intercepted a ship off the coast of Somalia bound for the Houthi-controlled parts of Yemen that was carrying Iranian-made missile components, Central Command said in a statement. That operation resulted in the deaths of two Navy SEALs who fell overboard while attempting to board the boat, CENTCOM said.
The US also carried out all of its attacks on Houthi targets unilaterally last week, in contrast to the coalition of countries that supported the first round of joint US and UK attacks on the Houthis on January 11.
Singh said Thursday that future joint operations are not off the table, but that CENTCOM Commander Gen. Erik Kurilla has the authority to order attacks if he deems it necessary, targeting ships in the region, including U.S. naval installations stationed in the Red Sea protect . After each of the attacks the U.S. launched against the Houthis last week, CENTCOM said the missiles destroyed by the U.S. were being prepared for impending launch by the Houthis.
National Security Council Strategic Communications Coordinator John Kirby told reporters on Thursday that with every attack on their infrastructure, the government is making it “harder” for the Houthis to continue their attacks. And he noted that the government has “additional options” available if the Houthis do not stop. However, he declined to preview what those options might look like.
“I'm not going to throw punches one way or the other, except to say what the president said this morning: If the Houthis continue down this path, we will continue to do everything we can to disrupt their ability and “Make those decisions,” he said.
“We don’t expect any conflict with the Houthis, we don’t expect any conflict in the region,” he added. “But we must be able to act in our own self-defense, not just for our ships and our sailors, but also for merchant ships and merchant seafarers and for international shipping in the Red Sea.”
This story has been updated with additional details.
CNN's Ruba Alhenawi contributed to this report.