Robert Mugabe's successor and the man appointed to lead Zimbabwe into its new era is due to fly back from exile on Wednesday afternoon and be sworn in as president on Friday.

Former vice president Emmerson Mnangagwa, who fled for his safety after Mugabe sacked him two weeks ago, will land at Manyame Airbase in Harare at 6pm (1600 GMT), after a military takeover ousted the 93-year-old Mugabe from power.

Last night Mnangagwa hailed 'God bless Zimbabwe' as he congratulated the people on reaching the 'historic' moment after 37 years of Mugabe rule.

'Together, we will ensure a peaceful transition to the consolidation of our democracy, and bring in a fresh start for all Zimbabweans and foster peace and unity,' he told Zimbabwe's Newsday.

'As I make my way back home, I look forward together with you the people of Zimbabwe to tackle the political and economic challenges facing our beloved country Zimbabwe. God bless Zimbabwe.'

Mugabe's downfall came suddenly for a man once feted across Africa as a liberation hero for leading his country to independence from Britain in 1980 after a war.

The 'grand old man' of African politics had clung on for a week after the army takeover, with the ruling ZANU-PF party urging him to go. He finally resigned on Tuesday moments after parliament began an impeachment process seen as the only legal way to force him out.

People danced in the streets of Harare and car horns blared at the news that the Mugabe era was finally over. Some brandished posters of Mnangagwa and army chief General Constantino Chiwenga.

Mugabe led Zimbabwe from relative prosperity to economic ruin, presiding over the forced takeover of white-owned farms at the end of the century, which devastated agricultural foreign exchange earnings and led to hyperinflation.

Alleged human rights abuses and flawed elections prompted many Western countries to impose sanctions in the early-2000s, that worsened the economic problems.

Though new investment from China softened the blow, most of Zimbabwe's 16 million people remain poor, squeezed by chronic currency shortages and sky-high unemployment.

If Mnangagwa can arrest Zimbabwe's economic decline, deliver clean elections next year and woo back bilateral support from Western states, new investment could begin to flow.

However, there are doubts about Mnangagwa's reform credentials, while a large section of the Zimbabwean public are hostile towards a man who, like Mugabe, stands accused of participating in repression.

He was internal security chief in the mid-1980s when Mugabe deployed a North Korean-trained brigade against rebels during which 20,000 civilians were killed, according to rights groups.

'The dark past is not going to disappear. They will be following him around like a piece of chewing gum on his shoe,' International Crisis Group's southern Africa senior consultant Piers Pigou said.

'For him to really be seen to be doing the right thing, he's going to have to introduce policies that fundamentally undermine the power structures of Zanu-PF, through a shift to genuine political pluralism and a decoupling of the party and state.'

Nicknamed 'Ngwena', or 'crocodile' in the Shona language, an animal famed in Zimbabwean lore for its stealth and ruthlessness, Mnangagwa issued a statement from hiding on Tuesday calling on Zimbabweans to unite to rebuild the country.

Additional reporting from Reuters.