Robert Mugabe has been removed as president of Zimbabwe's ruling ZANU-PF party and replaced by his former vice president Emmerson Mnangagwa, a party delegate told AFP on Sunday outside a meeting in Harare.

“A resolution has been adopted to recall the president and elevate Mnangagwa as the party president,” said the delegate, who declined to be named.

With the latest development, President Robert Mugabe was set to face the imminent collapse of his 37-year regime.

Mugabe's grip on power was broken last week when the military took over after his wife Grace emerged as the leading candidate to succeed the 93-year-old president, who is the world's oldest head of state.

On Saturday, tens of thousands of overjoyed protesters flooded the streets of Zimbabwe in peaceful celebrations marking the apparent end of his long and authoritarian rule.

“We meet here today with a heavy heart,” party official Obert Mpofu told the ZANU-PF meeting in Harare on Sunday, referring to Mugabe as “the outgoing president”.

“[Mugabe's] wife and close associates have taken advantage of his frail condition to usurp power and loot state resources,” he said.

“Our people are demanding... the recall of the president and first secretary of ZANU-PF from his position in the party,” he added.

Earlier in the day, the influential ZANU-PF Youth League reversed its previous devotion to Mugabe, saying that he must resign and Grace must be expelled from the party.

Historic week

Zimbabweans have experienced a historic week in which the military seized power and put Mugabe under house arrest in response to his sacking of vice president Emmerson Mnangagwa, the chief rival of Mugabe's powerful 52-year-old wife Grace.

On Saturday, in scenes of public euphoria not seen since Zimbabwe's independence in 1980, huge crowds marched and sang their way through Harare and other cities.

The demonstrations included citizens of all ages, jubilant that Mugabe appeared to be on his way out. In central Harare, a group of young men tore down a green metal street sign bearing Robert Mugabe's name and smashed it repeatedly on the road.

Such open dissent would have just a week ago would have been routinely crushed by security forces.

Sources suggest Mugabe has been battling to delay to his exit and to secure a deal guaranteeing future protection for him and his family. The succession race that triggered Zimbabwe's sudden crisis was between party hardliner Mnangagwa — known as the Crocodile — and a group called “Generation 40” or “G40” because its members are generally younger, which campaigned for Grace's cause.

“She is very acceptable. Very much accepted by the people,” Mugabe said of Grace in a faltering interview to mark his 93rd birthday last February.

The president, who is feted in parts of Africa as the continent's last surviving liberation leader, is increasingly fragile health, but previously said he would stand in elections next year that could see him remain in power until aged nearly 100.

He became prime minister on Zimbabwe's independence from Britain in 1980 and then president in 1987.