The massive march roamed several streets in the city of Taiz to voice support for Hadi's legitimacy and denounce what they described as a coup by the Shiite Houthi movement, according to eyewitnesses.
Demonstrators also expressed support to q statement issued by Hadi on Saturday from the southern city of Aden, in which he deemed all decisions taken by the Houthi group since Sept. 21 of 2014 "null" and "illegitimate."
In his first statement from the southern province of Aden following his escape from capital Sanaa where he was under house arrest, Hadi said that he would only abide by a Gulf initiative for solving the political crisis in Yemen as well as the results of his country's national dialogue.
The Yemeni leader resigned last month after the Houthis seized control of Sanaa's presidential compound, following clashes with presidential guards.
Describing the Houthi takeover of Sanaa as a "coup", Hadi said all moves made since then, a period in which the Houthis forced him to accept a power sharing agreement and later dissolved the parliament and set up a new ruling council, were illegitimate.
A statement made by the Houthis on Saturday accused the ousted president of working for foreign interests and denied he had been held under house arrest.
Hadi fled his residence in disguise, Houthi politburo member Ali al-Qahoum was quoted as saying by the local news website al-Akhbar. But he added that it no longer mattered if the former president remained there or departed.
Hadi's Sanaa residence was looted by Houthi militiamen after he left, witnesses said, but that was denied by Qahoum.
The Houthi group seized control of capital Sanaa in September and has since sought to expand its influence to other parts of the country.
Earlier this month, the Houthis issued what they described as a constitutional declaration, dissolving Yemen's parliament and establishing a 551-member transitional council.
The declaration was rejected by most of Yemen's political forces – along with some neighboring countries – which described it as a "coup against constitutional legitimacy."