Zimbabwe's Zanu-PF youths say they are "prepared to die" in defence of President Robert Mugabe's government, a day after the military threatened to intervene if the nonagenarian doesn't rein in his warring Zanu-PF lieutenants.

In a statement on Tuesday, Zanu-PF's secretary of the youth league Kudzai Chipanga said that Zanu-PF youths did not take lightly the military's threats.

"We as Zanu-PF youth league are a lion which has awakened and found its voice, therefore we will not sit idly and fold our hands whilst cheap potshots and threats are made against Mugabe," Chipanga said.

The southern African country's defence forces commander Constantino Chiwenga on Monday demanded a "stop" to the purges in the ruling Zanu-PF party following the sacking of vice president Emmerson Mnangagwa.

Chiwenga criticised the instability in the revolutionary party.

He accused the party of expelling senior officials who participated in the 1970s war against white-minority ruled Rhodesia; saying "counter revolutionaries" were plotting to destroy the party.

"The current purging and cleansing process in Zanu-PF which so far is targeting mostly members associated with our liberation history is a serious cause for concern for us in the defense forces," said Chiwenga.

He added: "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. The current purging of which is clearly targeting members of the party with a liberation background must stop forthwith."

But in his response, Chipanga maintained that the threats by the military chief were in violation of the country's constitution and as the youth league they were prepared to defend Mugabe.

"Defending the revolution and our leader and president is an ideal we live for and if need be it is a principle we are prepared to die for. This is an assault on our freedom as we now have a new constitution which places soldiers in barracks and civilian authority in power… The guns will follow the politics and not the politics following the guns. Cde Chiwenga, therefore, cannot be allowed to dictate who will lead the party and the country," said Chipanga.

Chipanga also demanded that the army chief accounts for "the $15bn that he stole with former vice president Mnangagwa."