US forces including B2 long-range stealth bombers attacked several underground Houthi weapons caches throughout Yemen early on Thursday.

This is the first known case of the western military using such aircraft to attack Houthi targets.

According to a statement by US Central Command (Centcom), the “precision strikes” targeted “hardened underground facilities” containing “missiles, weapons components and other munitions used to target US and international military and civilian vessels” in the Red Sea and the Gulf of Aden.

Assessment of the strike's impact is underway, Centcom added.

The Houthis military spokesman has not officially commented on the US attack yet.

Iranian news outlet Press TV, however, said the targets were carried out in Sana’a and Sa’ada and cited one Houthi official as saying that the Yemeni rebels will not change their stance to attack what they consider as western-linked shipping in response to Israel’s war in Gaza and the Lebanon.

The Yemeni rebels’ “capabilities are increasing” and a “response to the US-UK attacks [is] imminent,” Press TV said, citing the unidentified official.

The Houthis have attacked more than 100 civilian vessels with missiles, air and sea drones since last November, hijacking one ship, sinking two and damaging dozens of others.

At least three seafarers were killed in the process and another 25 have been in Houthi captivity for 11 months.

Commercial sea traffic though the Red Sea has been cut by about half, upsetting and diverting international trade flows.

The US has repeatedly claimed in the past to be degrading Houthi capabilities. The frequency of Houthi attacks has indeed markedly slowed down in recent weeks, with civilian vessels being targeted on just two occasions since 1 September.

It is unclear, however, if the slowdown is due to reduced Houthi capacity to carry out strikes or if the Yemeni rebels are simply running out vessels to strike as potential targets prefer sailing around Africa rather than going through the Red Sea.

Several maritime security and foreign policy experts have expressed the opinion that western governments have very few tools at their disposal to subdue the Houthis and end the crisis in the Red Sea.

On 27 September, the Iran-backed rebels claimed to have launched 23 missile and drones against three US warships in the Red Sea.

The Pentagon confirmed a “complex” Houthi attack took place against its ships but said that none of them came to harm.