The death was first announced on Monday by the Sanaa-based interior ministry, controlled by Saleh’s allies-turned-foes, the Houthi rebel group.
His killing was later confirmed to Al Jazeera by Saleh’s political party, the General People’s Congress (GPC).
Footage circulating on social media appeared to display a body resembling Saleh, with one video showing how armed militia members used a blanket to move the corpse into the back of a pick-up truck.
There were earlier reports that the Houthi rebels blew up one of Saleh’s houses, after storming the property.
Houthi sources said Saleh was killed by the rebels in a rocket-propelled grenade and shooting attack on his car at a checkpoint outside Sanaa.
Aref al-Zouka , the GPC’s secretary-general, was also killed.
In a statement read out on a Houthi TV network, the interior ministry announced the “killing” of “Saleh and his supporters”.
“This is after he and his men blockaded the roads and killed civilians in a clear collaboration with the enemy countries of the coalition,” the statement said.
The ministry also said its forces had “taken over all the positions and strongholds of the treacherous militia in the capital, Sanaa, and the surrounding areas, as well as other provinces in order to impose security”.
Sources close to Saleh told Al Jazeera that the head of the former president’s security detail, Hussein al-Hamidi, was among those killed, but did not provide further details.
Saleh was killed two days after he publicly broke off ties with the Houthi group, amid intense street battles between the rival factions that led to the killing of dozens of people.
In a televised statement on Saturday, he expressed his openness to talks with the Saudi-led coalition in what the Iran-aligned Houthi rebels labelled “a coup” against their fragile alliance.
2 days before he was killed, this was ex Yemeni president Saleh's last appearance on his TV station calling on his supporters to confront his former allies, the Houthis https://t.co/HNLBXFS7uo
— Mohamed Yehia (@yeh1a) December 4, 2017
Earlier on Monday, a Sanaa-based activist told Al Jazeera the Houthis had gained control of most of Sanaa from Saleh’s forces.
“Only small pockets remain,” Hussain Albukhaiti, who has close ties to the Iranian-backed Houthis, said.
Albukhaiti said that fighters had secured key areas south of the capital, including the “very strategic” al-Mesbahi residential area, which is approximately 200 metres from Saleh’s home.
A dominant figure in Yemen, Saleh, 75, ruled the Arabian Peninsula country for more than three decades before being deposed in 2012.
He remained, however, a key player in the years that followed and played a pivotal role in the country’s ongoing conflict.
The Houthi rebels, who are believed to be backed by Iran, stormed Sanaa in September 2014.
They seized control of the city and eventually forced President Abd-Rabbu Mansour Hadi, who succeeded Saleh in 2012, to flee to Saudi Arabia.
In March 2015, a Saudi-led coalition intervened to reinstate Hadi’s government.
Three months later, following Saudi-led coalition air raids on his home in Sanaa, Saleh officially announced for the first time the establishment of his alliance with the Houthi leadership.
Speaking to Al Jazeera from Sanaa, Hakim al-Masmari, editor-in-chief of the Yemen Post, described Saleh as “probably the most powerful person” in Yemen and said the reports of his death had left the country “in shock and awe”.
“You can not say this is the end of his political movement, but it’s a very big blow,” he said.
“But this is far from over – Saleh was an icon in Yemen for millions, and so his death will not go slowly or unanswered.”
The tactical Saleh-Houthi alliance had often appeared fragile, with both groups suspicious of each other’s ultimate motives and sharing little ideological ground.
“This will not bring Yemen any closer to an end in fighting,” said Masmari.
“We can only be sure that the Houthis are now united under one leadership. Before there were two leaderships, two different agendas, two different ways how to win the war.”
The war in Yemen is the worst humanitarian crisis in the world, according to the UN, killing at least 10,000 people and leading to widespread hunger and disease.
The UN called for an urgent humanitarian pause for Tuesday in Sanaa, saying it has become a battleground with people trapped in their homes.
“I call on all parties to the conflict to urgently enable a humanitarian pause on Tuesday 5 December, between 10am and 4pm to allow civilians to leave their homes and seek assistance and protection and to facilitate the movement of aid workers to ensure the continuity of life-saving programmes,” Jamie McGoldrick, the UN humanitarian coordinator for Yemen, said in a statement on Monday.
Noting concerns over the continued violence in Sanaa, McGoldrick said dozens of deaths and hundreds of injuries have been reported, including civilians.
“The streets of Sanaa city have become battlegrounds and people are trapped in their homes, unable to move out in search of safety and medical care and to access basic supplies such as food, fuel and safe water,” he said.
McGoldrick warned the warring sides that the deliberate attacks on civilians, including humanitarian and medical personnel, and against civilian and medical infrastructure, are “clear violations of international humanitarian law and may constitute war crimes”.
Marwan Bishara, Al Jazeera’s senior political analyst, described Saleh’s death as “a major turning point in Yemen’s history”.
“Saleh was a man for all seasons, someone who was able for four decades to change his political colours and alliances according to circumstances, up and until his death just a few hours ago,” he said.