It is still unclear who ordered the military movement, though it comes amid an unprecedented challenge to the 93-year-old president from the armed forces.
On Tuesday, several armoured vehicles spotted outside Harare alarmed many residents as Chiwenga had warned of possible military intervention.
"Please continue with your lives and face up to your own problems", tweeted the country's ruling party, the Zimbabwe African National Union Patriotic Front (Zanu-PF).
Ninety-three year old President Robert Mugabe of Zimbabwe is in trouble.
Here are some of the reactions from reports of tanks being seen heading to Harare.
Although the ruling ZANU-PF party has said it would never succumb to military pressure.
Now-sacked vice president Mnangagwa, 75, a long-serving veteran of Zimbabwe's 1970s liberation wars, had been viewed as a likely successor to Mugabe before the president fired him on November 6.
President Robert Mugabe's ruling party stripped Emmerson Mnangagwa of his vice president post.
"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", said General Constantino Chiwenga in a statement.
Mugabe has broken with most of his allies who fought in the liberation war against the white-minority regime of Rhodesia, leaving the so-called Generation-40 faction of younger members of the ruling party championed by his wife, Grace Mugabe, 52, in the ascendancy.
The former junior administrator is detested by numerous independence-era war veterans, who once enjoyed a privileged role in the ruling party under Mugabe, but who have increasingly been banished from senior government and party roles in recent years.
Addressing a press conference in the capital, Chiwenga, a perceived Mnangagwa loyalist, said the purges must stop. He has to declare his allegiance.
"What we are witnessing is the military saying: "We are willing to intervene if the red line is crossed".
The cordoning off of ZBC premises was also in line with upped security in the southern African country amid a political impasse, the website said.