The Saudi-backed presidential council in Yemen has expelled the leader of a separatist group and charged him with treason after he failed to fly to Riyadh for talks.

Six other members of the presidency accused Aidarous al-Zubaidi, head of the United Arab Emirates-backed Southern Transitional Council (STC), of undermining the independence of the republic.

A Saudi-led military coalition said Zubaidi fled after not joining STC officials on a flight from Aden and moved a large force to al-Dahle province. Coalition aircraft launched strikes on the forces in response, it added.

The STC said the strikes, which reportedly killed four people, were unjustified and that Zubaidi was still in Aden.

It also expressed concern that contact had been lost with the group's delegation in Riyadh.

The past few weeks have seen southern Yemen moving to the brink of a new conflict, with factions battling the Iran-backed Houthi movement in the country's decade-long civil war. The STC has taken control of much of the south and seeks independence from the internationally recognized government, which is backed by Saudi Arabia.

In December, STC's forces launched offensives to seize the eastern provinces of Hadramawt and al-Mahra. However, Saudi Arabia warned last week that these advances posed threats to its national security. It also accused the UAE of pressuring separatists for territorial expansion.

The situation escalated when, ahead of planned talks, Zubaidi failed to board a flight to Riyadh and was reportedly linked to a buildup of military resources. Coalition strikes targeted these forces, resulting in civilian casualties. The presidential council has since issued a decree stripping Zubaidi of his membership and referring him for prosecution.

The STC vowed to engage responsibly in diplomatic efforts despite the turmoil, indicating ongoing instability as various factions clash over control and influence in Yemen.