MUKALLA (AFP) — Yemen’s Saudi-led coalition attacked the home province of a United Arab Emirates (UAE)-backed separatist leader Wednesday after he was kicked out of the presidency and accused of “high treason” for attempting to secede.

More than 15 airstrikes hit Dhale, home governorate of Aidaros Alzubidi, whose Southern Transitional Council (STC) grabbed swathes of territory last month before seeing the advance rolled back by the coalition and pro-Saudi forces.

Four people were killed in the airstrikes, two hospital sources told Agence France-Presse (AFP).

Alzubidi fled and mobilized “large forces” in Yemen’s southwest, around Aden, after failing to attend talks in Riyadh, the coalition said.

The latest developments raise the prospect of a showdown between the UAE-supported STC and pro-Saudi forces around Aden, base of the internationally recognized government since it was ousted from the capital, Sanaa, by Iran-backed Houthi rebels in 2014.

The STC’s advance and the firm response from Saudi Arabia has sent relations with the UAE, fellow oil power and rival powerbroker in Yemen, plummeting.

Alzubidi “fled to an unknown location... after he had distributed weapons and ammunition to dozens of elements inside Aden,” coalition spokesperson Major General Turki al-Maliki said in a statement.

The coalition carried out new strikes to prevent Alzubidi from “escalating the conflict” and extending it into Dhale governorate, he said.

Alzubidi had been due to travel to the Saudi capital Riyadh on Tuesday for talks aimed at easing the clashes.

But his plane was delayed and he was not on board when it departed, the coalition said.

An STC official told AFP that Alzubidi decided not to fly to Saudi Arabia after receiving information that he would be asked to dissolve the group, which forms part of the Presidential Leadership Council.

The official said the delegation left for Riyadh without Aidaros.

In a statement, the Presidential Leadership Council, which holds executive power and groups rival factions, announced Alzubidi’s removal, accusing him of high treason.

“It has been established that (Alzubidi) has abused the just cause of the South and exploited it to commit grave crimes against civilians in the southern governorates,” it said.

More than 100 people have been killed in the airstrikes by the Saudi-led coalition on the newly-seized separatist positions in the southern governorates.

The Saudis and Emiratis have long supported rival factions in Yemen’s fractious government. They had initially joined forces in the Saudi-led military coalition against the Houthis.