- Gunfire erupted near President Robert Mugabe's private residence in Harare in the early hours of Wednesday
- Mugabe's Zanu-PF party accused army chief General Constantino Chiwenga on Tuesday of "treasonable conduct".
Military vehicles took to the streets of the Zimbabwean capital and prolonged gunfire was heard near the presidential residence early Wednesday as questions mounted over Robert Mugabe's grip on power, even as the army denied a coup in a state broadcast.
Tensions between the 93-year-old leader and the military that has helped prop up his reign have intensified in recent days, with Mugabe's Zanu-PF party on Tuesday accusing army chief General Constantino Chiwenga of "treasonable conduct".
The military's actions have been seen as a major challenge to Mugabe, but Major General Sibusiso Moyo went on state television in the early hours of Wednesday to deny the army was targeting the increasingly frail leader.
"It is not a military takeover of government," Moyo said, reading a statement.
"We wish to assure the nation that his excellency the president... and his family are safe and sound and their security is guaranteed.
"We are only targeting criminals around him who are committing crimes... As soon as we have accomplished our mission we expect that the situation will return to normalcy," he added.
Chiwenga had earlier demanded that Mugabe, who has ruled the country since independence from Britain in 1980, stop purges of senior party figures, including vice president Emmerson Mnangagwa, who was dismissed last week.
Zanu-PF said Chiwenga's stance was "clearly calculated to disturb national peace... and suggests treasonable conduct on his part as this was meant to incite insurrection".
Before being ousted, Mnangagwa had clashed repeatedly with Mugabe's wife Grace, 52, who is seen as vying with Mnangagwa to be the next president.
As the situation deteriorated overnight, the US embassy in Harare warned its citizens in the country to "shelter in place" due to "ongoing political uncertainty".
Prolonged gunfire erupted near Mugabe's private residence in the suburb of Borrowdale early Wednesday, a witness said. No further details were available.
The armoured vehicles spotted outside Harare also alarmed residents as Chiwenga had warned of possible military intervention. The army's spokesman was not available to comment.
"We very rarely see tanks on the roads," Derek Matyszak, an analyst at the Pretoria-based Institute for Security Studies, said.
"Chiwenga threw down the gauntlet to Mugabe... it would make sense for Chiwenga to organise some military manoeuvres to up the ante.