By Mohammed Mukhashaf
ADEN (Reuters) - Tens of thousands of Yemenis protested in Aden on Thursday against President Abd-Rabbu Mansour Hadi's sacking of the provincial governor and a cabinet minister widely praised for helping drive Iran-aligned Houthis from the city in 2015.
The two men sacked, Aden provincial governor Aydaroos al-Zubaidi and cabinet member Hani bin Brek, are both seen as supporting separatism for southern Yemen, while Hadi is determined to tighten his grip over a unified country.
Zubaidi was one of the leaders of the Southern Resistance that helped expel the Houthis from his city.
Diplomats and some analysts say Hadi is uncomfortable with the fact that among the forces trained and supported by the United Arab Emirates are some pro-secessionist fighters.
Zubaidi and Brek are also seen as close to the UAE, a powerful regional military player.
Witnesses described convoys of buses and cars carrying hundreds of people that had been arriving since Wednesday from around southern Yemen in Aden, the capital of the former South Yemen, for a rally billed as "a gathering of millions".
"Hadi is going along partisan objectives and deepening divisions in the country," said protester Hamed Faraj.
He said many people believe that the dismissals show the president is caving in to pressure from the Islamist Islah party, Yemen's branch of the Muslim Brotherhood, which also opposes the secessionist movement.
Zubaidi told the protesters that he intended to work with all parties to push for independence for the south.
"May 4th represents a turning point in the Southern nationalist movement's struggle for independence," he told the protesters in Aden.
Formerly Marxist South Yemen merged with the North in 1990. Secessionists failed in a civil war in 1994 to reverse the unification, but secessionist sentiment has picked up again in recent years.
Separatists accuse Hadi's government of failing to provide public services to Aden nearly two years after local fighters, backed mainly by forces from the UAE, expelled Houthis in 2015.
(This story refiles to add dropped word "are" in paragraph 2 to say "are both seen as supporting separatism".)
(Writing by Sami Aboudi; Editing by Hugh Lawson)