ADDIS ABABA, The Zimbabwean military’s takeover of power and detention of President Robert Mugabe “seems like a coup”, key regional bloc the African Union says.

Its head, Alpha Conde, said the AU demands an immediate return to constitutional order.

The military denies staging a coup, saying that Mugabe is safe and that it was acting against “criminals” surrounding him.

Their move follows a power struggle over who might replace Mugabe.

His vice-president, Emmerson Mnangagwa was fired last week, making Mugabe’s wife Grace the president’s likely successor – but leaving top military officials feeling sidelined.

Mugabe, 93, has dominated the country’s political scene since it gained independence from the UK in 1980.

Responding to the developments, Conde, who is also Guinea’s president, said Zimbabwean soldiers “had obviously attempted to take power”.

The AU had “serious concern” at the situation and “reiterates its full support to the country’s legal institutions”, the statement said.

After days of tension and rumour, soldiers seized the state broadcaster ZBC late on Tuesday.

A Zimbabwean army officer, Major General Sibusiso Moyo, went on air to say the military was targeting “criminals” around President Mugabe.

“This is not a military takeover of government,” he insisted.

Maj Gen Moyo also said Mugabe and his family were “safe and sound and their security is guaranteed”. It is not clear who is leading the military action.

Since then, military vehicles have been out on the streets of Harare, while gunfire has been heard from northern suburbs where Mugabe and a number of government officials live.

In a statement, the office of South African President Jacob Zuma, said: “President Zuma spoke to President Robert Mugabe earlier today who indicated that he was confined to his home but said that he was fine.”

There has been no direct comment from President Mugabe, nor his wife Grace, whose whereabouts are unclear.

The rivalry between Grace and Mnangagwa has split the governing Zanu-PF.

Following a call for his dismissal from Grace, Mnangagwa was removed from the vice presidency.

But, army chief Gen Constantino Chiwenga said the army was prepared to act to end purges within Zanu-PF.

Gen Chiwenga is a close ally of Mnangagwa and both are veterans of the 1970s war which ended white minority rule.

A supporter of Grace, Zanu-PF youth wing leader, Kudzai Chipanga, had responded by saying the military should “stay in the barracks”.

But he has now apologised to Gen Chiwenga and other top military officials, saying “we are still young and make mistakes”, ZBC reports.