The Associated Press reported seeing armed soldiers assaulting civilians and loading ammunition into military vehicles. Firstly, we wish to assure the nation that His Excellency the President of the Republic of Zimbabwe, and commander-in-chief of Zimbabwe Defence Forces, Comrade RG Mugabe, and his family are safe and sound and their security is guaranteed.
"We are only targeting criminals around him who are committing crimes. that are causing social and economic suffering in the country".
In the broadcast, the spokesman said the military expected "normalcy" to return as soon as the army had completed its "mission".
"The current purging, which is clearly targeting members of the party with a liberation background, must stop forthwith", Mr Chiwenga said in a statement read to reporters at a news conference packed with senior officers.
Mr. Mugabe took power in 1980, leading what was then a promising African nation away from white colonial power.
Tensions between the 93-year-old leader and the military have intensified in recent days.
Mugabe's ZANU-PF party accused army chief General Constantino Chiwenga on Tuesday of "treasonable conduct".
For decades general Mnangagwa, known as the Crocodile, was at President Mugabe of Zimbabwe's side, an ally who was relied on to do the dirty work and was described as the one person more feared than his boss.
As the situation deteriorated overnight, prolonged gunfire was heard near Mugabe's private residence.
Soldiers 'take over Zimbabwe's state broadcaster' as explosions heard in Harare
In a message posted online Tuesday night, the embassy also instructed USA government personnel in Zimbabwe to remain in their residences and work from home on Wednesday. The army meanwhile said on state television that it was not a coup.
Robert Mugabe also owns Hamilton Palace in Sussex which cost $40 million (£30 million) which has since been left a derelict construction site.
As that political momentum began to fade, Mugabe moved to quickly consolidate power using a combination of brutality and bribery, according to CNN's Robyn Curnow, who has reported from the region for years.
The main opposition MDC party called for civilian rule to be protected. If the army takes over that will be undesirable.
Mnangagwa, 75, was widely considered most likely to succeed Mugabe.
Earlier this year the country was gripped by a freaky spat between Grace and Mnangagwa that included an alleged ice-cream poisoning incident that laid bare the pair's rivalry. The same year, Grace Mugabe was appointed to head the ruling party's women's league. Mugabe denied the charges, but was granted diplomatic immunity before she could make a court appearance.
Theresa May launches attack on Russian election 'meddling'
May said Russia's "illegal annexation of Crimea" was the first time since the Second World War that a sovereign nation has forcibly taken territory from another in Europe. "We know what YOU are doing as well".