Some of the army top brass are seen as strongly opposed to Grace Mugabe's apparent emergence as the likely next president.
"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", Chiwenga said in a statement read to reporters at the news conference.
eNCA's Zimbabwean correspondent Pindai Dube confirmed the tanks were visible in the streets of Harare, with sources indicating it was a "show of force" rather than a coup.
"As a result of squabbling within the ranks of Zanu-PF, there has been no meaningful development in the country for the past five years".
Mnangagwa was subsequently fired from the party and has since left the country.
Chiwenga on Monday issued a hard hitting statement urging the ruling party to stop expulsion of party members with a liberation war background.
Addressing a press conference in the capital, Chiwenga, a perceived Mnangagwa loyalist, said the purges must stop.
Grace, now poised to become a vice president, did not fight in the liberation war.
Sweden shatter Italy's World Cup dream
The big news from the first leg is that Marco Verratti will miss the second contest after picking up a yellow card in Sweden. Immbobile beat Olsen with another but Andreas Granqvist got back for a decisive goal-line clearance.
Samsung CONFIRMS Galaxy A5 2018 Via Support Page
It is speculated that this particular model of the A series will bag an improved camera, in comparison to its predecessors. Apart from the FCC certification, the South Korean website also authenticated the arrival of the A5.
Former Irish global Liam Miller is battling cancer
The Ireland midfielder David Meyler said: "Thoughts go out to him and his family, from the whole team". Miller started his professional career with Celtic before moving to United in the summer of 2004.
Idea Cellular reports Q2 net loss of Rs 1106.8 crore
That move comes as Idea and Vodafone's India business get set to merge , and begin selling off assets for debt repayment. A hotel employee clears a table after Vodafone Group and Idea Cellular news conference in Mumbai, India March 20, 2017.