Zimbabwe's army chief has called for an immediate end to purges within President Robert Mugabe's ruling party following the dismissal last week of the country's vice president.

In a rare statement, General Constantino Chiwenga warned on Monday that the military could intervene if the infighting in the ruling Zimbabwe African National Union-Patriotic Front (ZANU-PF) did not stop.

"The current purging which is clearly targetting members of the party with a liberation background must stop forthwith," Chiwenga told a media conference in the capital, Harare.

"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," he said, adding that the instability was causing anxiety in the country.

Vice President Emmerson Mnangagwa, who joined the struggle for Zimbabwe's liberation struggle at a young age, was sacked by Mugabe on November 6 for showing "traits of disloyalty".

Explaining the reasons for Mnangagwa dismissal, information minister Simon Khaya Moyo said: "The vice president has consistently and persistently exhibited traits of disloyalty, disrespect, deceitfulness and unreliability.

"It had become evident that his conduct in his discharge of his duties had become inconsistent with his official responsibilities."

The expulsion of Mnangagwa, a former minister of defence and state security, had removed a potential successor to Mugabe, the 93-year-old president and leader of the ruling ZANU-PF party.

It had also cleared the way for Mugabe's wife, Grace, to succeed her husband. Zimbabwe's first lady leads the ruling party's Women's League, and has been endorsed as a potential candidate for the vice presidency by some structures within ZANU-PF.

The day before Mnangagwa's removal, Grace Mugabe called the vice president a "coup plotter" and a "coward" in a speech that shook ZANU-PF.

The speech came a day after Mugabe publicly criticised Mnangagwa for the first time during a speech at a rally on November 4.

Some powerful army generals backed Mnangagwa to succeed Mugabe and have publicly said they will not allow someone who did not fight in the 1970s independence war to rule. Grace Mugabe, 52, did not fight in that war.

Relations between Zimbabwe's leader and his former vice president soured in August after hints by Mnangagwa's allies that he had been poisoned by ice cream from a dairy owned by the Mugabes.

Mugabe, who has been leading Zimbabwe since it gained independence in 1980, intends to contest elections due next year and does not face a united opposition.