Tanks rolled towards Zimbabwe’s capital Harare on Tuesday, sparking international concern. Gun and artillery fire reportedly rang out in the northern parts of the city.

Then, in the early hours of Wednesday morning, the announcement came — the military had seized control of the country.

Residents said soldiers blocked access to government buildings and courts in the capital, while access to the President’s official residence was also sealed.

But the armed forces deny staging a military coup, saying that once they complete their “mission”, the country will return to “normalcy”.

Here, we explain what led to the current uncertain situation and consider what is next for the former British colony.

What reason is the military giving for the takeover?

After seizing control of state TV, an army spokesman announced the military was targeting people close to President Robert Mugabe, who has been in power since 1980.

A statement read aloud by Major General Sibusiso Moyo said the intervention was needed to stop criminal activity in the country.

“As soon as we have accomplished our mission, we expect that the situation will return to normalcy,” he said.

He said the army wanted to make it “abundantly clear” the move was not a military takeover.

Instead, he claimed: “What the Zimbabwe defence forces are doing is to pacify a degenerating political, social and economic situation in our country, which if not addressed may result in a violent event".

Gen Moyo gave assurances that the 93-year-old leader and his family were “safe and sound”. The South African President Jacob Zuma said he had since spoken to the leader, who told him he was under house arrest.

What is happening within the ruling Zanu PF party?

Mr Mugabe last week fired his deputy, Emmerson Mnangagwa, in favour of his wife, Grace. This placed the 53-year-old in a position to take over after her husband dies.

The rivalry between Ms Mugabe and Mr Mnangagwa – who is known as the “crocodile” – has split the ruling Zanu PF party.

Mr Mnangagwa, who fled Zimbabwe after he was sacked, has close ties to the armed forces and on Monday, the army said Zanu PF’s leadership was “clearly targeting” supporters of the ousted vice-president. It warned it would intervene if the party continued to purge Mr Mnangagwa’s allies.

A government source told Reuters the Finance Minister Ignatius Chombo had been detained during the military coup. Mr Chombo is a leading member of a faction of Zanu PF led by Ms Mugabe.

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How popular is Grace Mugabe?

There is limited support for the authoritarian ruler's wife because she is seen to spend lavishly spending as many in the country struggle. Pictures of one of her sons apparently pouring champagne over a luxury watch in a nightclub were shared widely on social media this week.

Ms Mugabe's reputation has also been tarnished after she was accused of assaulting a model in Johannesburg in September. She was granted diplomatic immunity after the incident and was allowed to leave South Africa after the incident and denies wrongdoing.

How powerful is Robert Mugabe?

Mr Mugabe has dominated the impoverished country's politics since it gained independence in 1980.

His authoritarian rule has previously been bolstered by strong support from the military, but in recent years he has dismissed a series of veterans of the liberation struggle from party posts.

War veterans broke ranks with him in 2016 and have vowed to form a broad front with the opposition to challenge his rule.

Some observers expect Mr Mugabe to stay on as a figurehead while Mr Mnangagwa and his allies run the country.