Zimbabwe's military read out a statement on national TV after seizing the national broadcaster ZBC, claiming the army was "targeting criminals" and was not staging a "military takeover of government." .
Spokesman Maj. Gen. Sibusiso Moyo said the military were not taking power and told viewers the president and his family were safe and their security was "guaranteed".
In the broadcast, Moyo spoke of targeting "criminals" around the president who are "committing crimes that are causing social and economic suffering in the country in order to bring them to justice".
According to the army general, they expect that the situation will return to normalcy "as soon as we have accomplished our mission".
Armoured vehicles were seen on the streets near the capital Harare as questions mounted over whether Mr Mugabe, who has ruled since independence from Britain in 1980, was still holding onto power.
The activity triggered speculation of a coup, but the military's supporters praised it as a "bloodless correction".
Due to ongoing uncertainty in Zimbabwe, the U.S. Embassy in Harare will be minimally staffed and closed to the public on November 15.
In response on Tuesday, Zimbabwe's ruling party accused the military chief of "treasonable conduct" for challenging its president.
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.
Mnangagwa had previously been considered most likely to succeed Mugabe if the president stepped down or died in office.
Notably though, the lead item on the ZBC state broadcaster's evening news bulletin was an anti-military rally by the youth wing of Mr Mugabe's ZANU-PF party - however the channel then missed its usual 11:00pm (local time) bulletin, without providing an explanation.
Grace Mugabe has drawn the ire of Zimbabweans for appearing to be out of touch.
President Mugabe has exerted nearly total authority over Zimbabwean politics for decades - but the sacking of his most senior long-time confidant "has laid bare the rivalries inside Zimbabwe's political establishment" and could spark repercussions beyond his control, says the Daily Mail.
But a recent post from the ruling party's own Twitter account suggests the first family has been detained.
Chombo was a leading member of the "G40" group in the ruling Zanu-PF party, led by Mugabe's wife Grace.
"Usually, the police support unit quickly rushes onto the streets and it was feared they would mobilise the youths and give them guns so they could fight back, but the military boxed them deep in the night and took over all strategic points there", a witness said.