The leader of Yemen’s presidential council declared a state of emergency and cancelled a security pact with the United Arab Emirates (UAE) on Tuesday after separatists seized swathes of territory.

“The joint defence agreement with the UAE is hereby cancelled,” a statement said, while a separate decree announced a 90-day state of emergency, including a 72-hour air, sea and land blockade.

The announcements by Rashad al-Alimi, head of the Presidential Leadership Council, come after the Saudi-led coalition fighting in divided Yemen said it struck a UAE weapons shipment destined for the separatists.

The Southern Transitional Council (STC) forces have swept through the south of Yemen this month, taking most of resource-rich Hadramawt province and swathes of neighbouring Mahrah.

Alimi ordered the SCT to hand over the territory to Saudi-backed forces, calling the separatists’ advance an “unacceptable rebellion” in a televised address.

The confrontation risks tearing apart the already fractured Yemeni government.

It also threatens slow-moving peace negotiations with the Houthis, who ousted the government from the capital Sanaa in 2014, triggering a military intervention by the Saudi-led coalition.

Saudi Arabia says its national security is a ‘red line’ after strike in Yemen

Saudi Arabia said on Tuesday its national security was a red line it would defend, hours after a Saudi-led coalition struck what it described as foreign military support to southern separatists at Yemen’s Mukalla port.

The Saudi foreign ministry said in a statement it hoped the UAE will take the necessary steps to preserve bilateral relations.

It also expressed “disappointment” over the actions taken by “brotherly UAE pressuring the STC’s forces to conduct military operations on the southern borders of the kingdom in the governorates of Hadramout and Al-Mahara, which is considered a threat to the kingdom’s national security, and the security and stability of the Republic of Yemen and the region“.

“The steps taken by the UAE are considered highly dangerous, inconsistent with the principles upon which the coalition to restore legitimacy in Yemen was established, and do not serve the coalition’s purpose of achieving security and stability for Yemen,” it said.

“In this context, the kingdom stresses that any threat to its national security is a red line, and the kingdom will not hesitate to take all necessary steps and measures to confront and neutralise any such threat,” it said.

“The kingdom also hopes that the brotherly UAE will take the necessary steps to preserve bilateral relations between the two brotherly countries, which the kingdom is keen on strengthening, and continue joint efforts towards all that leads to the well-being, prosperity and stability of countries in the region,” it added.