Saudi Arabia carried out airstrikes on the Yemeni port city of Mukalla on Tuesday, targeting what it said was a shipment of weapons intended for the UAE-backed Southern Transitional Council (STC). The kingdom warned that the actions of the Emirates in supporting the separatists’ advances in Yemen were “extremely dangerous,” highlighting a new escalation in tensions between Riyadh and Abu Dhabi.

The strike comes amid growing competition between Saudi Arabia and the UAE, which, while generally aligned on regional issues, have supported opposing sides in Yemen’s decade-long war against the Iranian-backed Houthi movement. Analysts note that the airstrike underscores wider friction in the Red Sea region, where both nations also have competing interests in Sudan and elsewhere.

Following the airstrike, Yemen’s anti-Houthi forces declared a state of emergency. The presidential council imposed a 72-hour ban on all border crossings under its control, as well as entries to airports and seaports, except those authorized by Saudi Arabia. The council additionally called for UAE forces to withdraw within 24 hours and canceled the security pact with Abu Dhabi.

According to a statement carried by the state-run Saudi Press Agency, the strikes targeted ships that arrived from Fujairah, a port city on the UAE’s eastern coast. “The ships’ crew had disabled tracking devices aboard the vessels and unloaded a large amount of weapons and combat vehicles in support of the Southern Transitional Council’s forces,” the statement said. “Considering that the aforementioned weapons constitute an imminent threat, and an escalation that threatens peace and stability, the Coalition Air Force has conducted this morning a limited air strike that targeted weapons and military vehicles offloaded from the two vessels in Mukalla.” Saudi authorities added that the attack was conducted overnight to minimize collateral damage.

It is not immediately clear whether other military forces participated in the strikes. The UAE did not respond to requests for comment. AIC, a Southern Transitional Council-linked news channel, acknowledged the strikes without providing further details. Analysts identified one targeted vessel as the Greenland, flagged in St. Kitts, which arrived in Mukalla on Sunday after leaving Fujairah on December 22. A second vessel has not yet been identified. Social media footage appeared to show armored vehicles moving through Mukalla following the shipment, corresponding with surveillance imagery aired later by Saudi state television.

Mukalla, located in Yemen’s Hadramout governorate, was recently seized by the STC. The port is roughly 480 kilometers northeast of Aden, the base of Yemen’s anti-Houthi forces. Saudi Arabia had previously targeted the STC in airstrikes on Friday as a warning to halt their advance in Hadramout and Mahra governorates. The Council had pushed out forces affiliated with the Saudi-backed National Shield Forces, while raising the South Yemen flag in demonstrations calling for renewed secession.

The strikes further strain relations between Riyadh and Abu Dhabi, which have previously cooperated in OPEC+ and regional initiatives but increasingly compete economically and politically. Saudi Foreign Ministry officials directly linked the STC’s advances to the UAE, stating: “The kingdom notes that the steps taken by the sisterly United Arab Emirates are extremely dangerous.”

The move also reflects concerns over broader security risks in the Red Sea region, as separate developments include Israel’s recognition of Somaliland, which has drawn threats from the Houthis. Analysts predict a calibrated escalation from both sides, with the STC likely to consolidate its control while Saudi Arabia seeks to curtail the flow of weapons. Mohammed al-Basha, a Yemen expert, noted, “I expect a calibrated escalation from both sides. The UAE-backed Southern Transitional Council is likely to respond by consolidating control. At the same time, the flow of weapons from the UAE to the STC is set to be curtailed following the port attack, particularly as Saudi Arabia controls the airspace.”

The Mukalla strike illustrates both the fragility of alliances in Yemen’s ongoing war and the risks of regional rivalry, highlighting the complex dynamics between Saudi Arabia, the UAE, and local actors in the southern governorates.