Yemen's Houthi movement declared a naval blockade against Saudi Arabia on Monday, ending years of relative calm along one of the Middle East's most sensitive frontlines and opening a new front in the wider regional standoff over Iran.

The Houthi armed forces said in a statement that they had imposed a maritime embargo against Saudi Arabia, describing it as retaliation based on "an eye for an eye," effective immediately. The group accused Saudi Arabia of maintaining an unjust and oppressive siege on Yemen for nearly 12 years, plundering the country's resources and blockading its ports and airports by land, sea and air. Houthi military spokesman Yahya Saree said militants were prepared to answer any Saudi retaliation with what he called total and harsh escalation.

The declaration follows an attack on Sanaa International Airport last week that pushed the two sides toward direct confrontation for the first time since an informal truce took hold in March 2022. The Houthis blamed Saudi Arabia for the strike, though Yemen's internationally recognized government, based in Aden, claimed responsibility itself, saying the action was intended to stop an Iranian aircraft from landing in the Houthi-controlled capital. That flight, arriving from Tehran on July 3, was reportedly the first publicly announced Iranian flight to reach Sanaa in more than a decade, and the Yemeni government has accused Tehran of using such flights to move military equipment to the Houthis.