However, Isaac Moyo, Zimbabwe's ambassador in South Africa, claimed the government remains "intact".
This came after reports emerging that the Zimbabwean soldiers with Zimbabwe Defense Forces (ZDF) reportedly seized control of the state broadcasting outlet in the wee hours of the Wednesday morning.
"We are only targeting criminals around who him who are committing crimes that are causing social and economic suffering in the country in order to bring them to justice".
Grace Mugabe, 52, has support in the party's youth wing and is believed to have engineered the firing of another vice president, Joice Mujuru, in 2014.
The US State Department is encouraging Americans in the country to "shelter in place until further notice" due to reports of violence and ongoing political unrest, while the UK Foreign Office said it is "monitoring the situation closely" and advised people to avoid demonstrations and rallies.
The attacks, which had the backing of President Mugabe, eventually led to the dismissal of the former vice president, who has strong backing from the military.
Magnitude Earthquake Strikes South Korean Coastline
Pohang is some 35km from the Wolseong Nuclear Power Plant, which has six operational reactors. Before the main tremor, earthquakes of 2.2 and 2.6 magnitude struck areas near Pohang city.
"We must remind those behind the current treacherous shenanigans that when it comes to matters of protecting our revolution, the military will not hesitate to step in", General Chiwenga said.
The announcement capped days of political surprises that started with the firing of Vice President Emmerson Mnangagwa last week, followed by a statement from the head of the armed forces, who warned Monday that the military will intervene if the purge continued.
"The government's silence on the military deployments seem to confirm that President Mugabe has lost control of the situation", Robert Besseling, of the London-based EXX Africa risk consultancy, said.
In an incendiary statement, Mugabe's ZANU-PF party accused army chief General Constantino Chiwenga of "treasonable conduct" for challenging Mugabe over the recent sacking of the vice president.
Mnangagwa's ouster marked a dramatic shift in politics in Zimbabwe, where he had been a pillar of a military and security apparatus that helped Mugabe emerge as the nation's leader after independence from the U.K.in 1980. "USA citizens in Zimbabwe are encouraged to shelter in place until further notice".
Robert Mugabe has accumulated a net worth of $10 million (£7.5 million) thanks largely to the fortunes reaped from Zimbabwe's diamond deposits. "From the direction of his house, we heard about 30 or 40 shots fired over three or four minutes soon after 2:00 am", a resident who lives close to Mugabe's mansion in the suburb of Borrowdale told AFP. Reuters said another two military vehicles were parked 20 miles (32km) from Harare.