Foes and supporters said Saleh was killed in a roadside ambush after switching sides in the civil war, abandoning his Iran-aligned Houthi allies in favour of the Saudi-led coalition.
Yasser al-Awadi, the GPC's assistant secretary-general, was also killed. It could easily kick off new violence between Saleh's supporters and Houthi militants.
The murder of Saleh has a different impact on Saudi Arabia and Iran, some analysts said. Before his killing, Saleh withdrew from the alliance with the Houthis and welcomed talks with Saudi Arabia on condition that it halts airstrikes and a blockade.
It was a bitter end for the former president who had ruled the north of Yemen and then a united north and south for almost 34 years.
"He was martyred in the defence of the republic", said Faiqa al-Sayyid, a GPC leader. He remained, however, a key player in the years that followed and played a pivotal role in the country's ongoing conflict.
Unverified footage circulated showing his bloodied body, just days after he tore up his alliance with the Houthis following almost three years in which they had jointly battled the Saudi-led coalition.
Speaking later on television, President Abedrabbo Mansour Hadi, the leader of the internationally recognized government, called on Yemenis to unite against the Huthis.
Sources in the Houthi militia said its fighters stopped Mr Saleh's armoured vehicle with an RPG rocket outside the embattled capital Sanaa and then shot him dead. Jamie McGoldrick, Yemen's Humanitarian Affairs Coordinator for the United Nations, warned that the death of Mr. Saleh would only lead to "more tragedy" in the country.
"You can not say this is the end of his political movement, but it's a very big blow", he said. Therefore, Houthis finally made a decision to kill him; not because he turned against them, but because he is capable of destroying their political project.Days ago, Saleh changed the map when he annulled his alliance with Houthis.
In a televised speech on Monday, Huthi made no mention of Saleh's death but expressed his satisfaction at the day's events. His death puts the exclamation point on the end of an era in Yemen that had, for all intents and purposes, already come to a close.
Former U.S. Diplomat David Mack, now with the Middle East Institute, told VOA Saleh was "one of the smartest political operatives in the Arab world", and the former president believed he had been unjustly driven from office by countries of the Gulf Cooperation Council, in accord with the United States. It was said that they were the strongest party, and that any attempt at driving them out would lead to a bloody war between the two parties in the city's historic streets.