The Saudi Arabia-led coalition in Yemen has announced that the leader of the secessionist Southern Transitional Council (STC) has fled to the United Arab Emirates via Somaliland after skipping planned peace talks in Riyadh, accusing the UAE of smuggling him out of the country.

In a statement on Thursday, the coalition said Aidarous al-Zubaidi “escaped in the dead of night” on Wednesday on board a vessel that departed Aden in Yemen for the port of Berbera in Somaliland.

Al-Zubaidi then boarded a plane along with UAE officers and flew to Somalia’s capital, Mogadishu. “The plane turned off its identification systems over the Gulf of Oman, then turned it back on 10 minutes prior to arrival at Al Reef military airport in Abu Dhabi,” the statement said.

There was no immediate comment from the STC or the UAE.

Somalia’s immigration authority said in a statement that it is investigating reports “concerning the alleged unauthorized use of Somalia’s national air space and airports to facilitate the movements of a fugitive political figure,” which it added would be a “serious violation” of the country’s sovereignty.

If confirmed, the move could deepen the feud between Saudi Arabia and the UAE that came to light after the STC, which Riyadh says is backed by Abu Dhabi, launched an offensive against Saudi-backed Yemeni government troops in December.

The STC – which initially supported Yemen’s internationally recognised government against the Houthi rebels in northern Yemen – is seeking an independent state in southern Yemen. It seized the provinces of Hadramout and al-Mahra, which border Saudi Arabia, in a campaign that Riyadh described as a red line for its national security.

The Saudi-led coalition responded with air strikes on the Yemeni port of Mukalla on December 30, targeting what it called a UAE-linked weapons shipment, and backed a call by Yemen’s internationally recognised government for Emirati forces to withdraw from the country.

For its part, Abu Dhabi denied that the shipment contained weapons and expressed a commitment to ensure Riyadh’s security. On the same day, it announced an end to what it called its “counterterrorism mission” in Yemen.

Yemeni government troops, backed by Saudi air attacks, went on to reclaim Hadramout and al-Mahra, and the STC said on Saturday that it would attend peace talks hosted by Riyadh.

But the coalition said al-Zubaidi was not on board the flight that took the STC delegation to Riyadh on Wednesday.

It launched strikes on al-Zubaidi’s forces in Yemen’s Al-Dale governorate, while the Yemeni government’s ground forces moved on the STC-controlled Aden and seized the presidential palace in the city.

On Thursday, the Saudi-backed Homeland Shield Forces said that they had arrived in Aden, and had began to secure the city.

Al-Zubaidi ‘a fugitive’

The head of the internationally recognised government’s Presidential Leadership Council, Rashad al-Alimi, has meanwhile announced that al-Zubaidi has been removed from the council for “committing high treason”.

Al-Alimi said he has asked the country’s attorney general to launch an investigation against al-Zubaidi and take legal action.

The Saudi ambassador to Yemen, Mohammed Al-Jaber, posted a picture with 19 officials on Thursday, saying he met the STC delegation and discussed a conference on South Yemen to be held in Riyadh soon.

He said al-Zubaidi’s actions “harmed the Southern cause and did not serve it, and damaged the unity of the front in confronting the enemies”, referring to the Houthis.

Mohammed Al-Ghaith, a senior official of the STC who is part of the delegation in Riyadh, said on Thursday that their delegation had held productive talks with the Saudi ambassador.

Al Jazeera correspondent Hashem Ahelbarra said that, having fled Yemen, al-Zubaidi was now out of the picture politically, as others within the STC were meeting the Saudis in Riyadh and would potentially take over as leaders of the movement.

“From a Saudi perspective, today he’s a fugitive,” said Ahelbarra.

“He had a chance to fly to Riyadh to negotiate a settlement. From now onwards, from a Saudi perspective, his era is over and that explains why some of his lieutenants are now in Riyadh, taking over as potential leaders.”

In particular, one of those present in Riyadh, Abdulrahman al-Mahrami, a senior STC official and commander of the Southern Giants Brigade, was likely to “have a bigger say in the future”, he said.

“He took over Aden yesterday, his troops are present there to prevent the secessionists from taking over,” said Ahelbarra.

“In a way, he is some sort of replacement for Aidarous al-Zubaidi.”

While only days ago, the STC had announced a move that it said would lead to an independent southern Yemeni state within years, “the idea of secession is no longer on the table.

“Now the talk is about a federal system with one authority,” he said.

Ahelbarra said the fallout from al-Zubaidi’s flight had exposed the rift between Saudi Arabia and the UAE like never before.

“You don’t get any sense of a compromise or an attempt at reconciliation,” he said.

“It gives you a sense that we are likely to see more strained relations in the upcoming days about the future of Yemen.”

He said the Saudis were insisting that the roadmap for Yemen would be resolved in Riyadh, and that they would tolerate no further dissent.

“It’s totally clear to me that they have the upper hand when it comes to how to go forward,” he said.

Separately on Thursday, Yemen’s ‍internationally recognised Presidential Leadership Council (PLC) dismissed Defence Minister ⁠Mohsen al-Daeri from the government, state news agency Saba ‍reported.