Zimbabwe's former army commander who led a military takeover that helped end Robert Mugabe's 37-year rule has been sworn in as one of the country's two vice presidents.

General Constantino Chiwenga, 61, took the oath of office in Harare, pledging to be "faithful" to Zimbabwe and to "obey, uphold and defend the constitution", said an AFP journalist who witnessed the ceremony.

"I will discharge my duties with all my strength and to the best of my knowledge and ability," Mr Chiwenga said.

He retired from the military last week, slightly over a month after the military temporarily took control of the country on 15 November, culminating in Mr Mugabe's resignation six days later.

Emmerson Mnangagwa, who had a few weeks earlier been sacked from his job as vice president by Mr Mugabe, then took over as the head of state.

Kembo Mohadi, a veteran politician and long-serving state security minister, was also sworn-in this morning as the second vice president to Mr Mnangagwa.

Mr Mugabe, 93, was ousted from power after the military stepped in following internal feuding and factionalism that had escalated in the ruling ZANU-PF party over who would succeed him.