Several armoured vehicles drove down main roads near the Zimbabwean capital Harare Tuesday, as tension erupted between President Robert Mugabe and the military that has been a key buttress to his 37-year reign.

In an incendiary statement, Mugabe's ZANU-PF party accused army Chief General Constantino Chiwenga of "treasonable conduct" for challenging Mugabe over the sacking of the vice president. The public dispute has presented a major test of whether 93-year-old Mugabe, who has ruled since independence from Britain in 1980, still has a firm grip on power.

Chiwenga had demanded that Mugabe 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 widely seen as vying with Mnangagwa to be the next president when Mugabe dies.,p> On Tuesday, several armoured vehicles spotted outside Harare alarmed many residents as Chiwenga had warned of possible military intervention.

The reason for the military presence was not clear, but the vehicles may have been on routine manoeuvres or a deliberate show of force. The army's spokesman was not available to comment. "I saw a long convoy of military vehicles," a female fruit seller about 10 kilometres (six miles) from central Harare, told AFP, while other witnesses took to social media to confirm the reports. Mugabe is the world's oldest head of state, but his frail health has fuelled a bitter succession battle as potential replacements jockey for position.

Some of the army top brass are seen as strongly opposed to Grace Mugabe's apparent emergence as the likely next president.

source: AFP