Zimbabwe’s military has read out a statement after taking over the national broadcaster, ZBC, saying it has taken action to “target criminals”.
However, it said this was not “a military takeover of government” and President Robert Mugabe was safe.
In a series of tweets, ruling party ZANU PF said “There was no coup, only a bloodless transition which saw corrupt and crooked persons being arrested and an elderly man who had been taken advantage of by his wife being detained. The few bangs that were heard were from crooks who were resisting arrest, but they are now detained.”
“Zimbabwe has not had a coup. There has been a decision to intervene because our constitution had been undermined, in the interim Comrade E Mnagngawa will be president of ZANU PF as per the constitution of our revolutionary organisation.”
Heavy gunfire and artillery were heard in northern suburbs of the capital, Harare, early on Wednesday.
Zimbabwe’s envoy to South Africa, Isaac Moyo, earlier dismissed talk of a coup, saying the government was “intact”.
The statement read out by Maj Gen Sibusiso Moyo came hours after soldiers overran the headquarters of ZBC. He said: “We wish to assure the nation that his excellency the president… and his family are safe and sound and their security is guaranteed.”
The statement added: “We are only targeting criminals around him who are committing crimes… that are causing social and economic suffering in the country. As soon as we have accomplished our mission, we expect that the situation will return to normalcy.”
The statement did not name those targeted but a government source quoted by Reuters said Finance Minister Ignatius Chombo was among those detained.
It is not clear who is leading the military action.
Alex Magaisa, former adviser to Zimbabwean opposition leader Morgan Tsvangirai, told the BBC he believes the military’s claim that they haven’t carried out a coup is untrue.
“They have decided not to call it a coup because they know that a coup does not sell, it will be condemned,” he said.
“But as far as authority is concerned it seems very clear that President Mugabe is now just a president in name and authority is now residing in the military.”
The latest events came hours after Zimbabwe’s ruling party accused the country’s army chief of “treasonable conduct” after he warned of possible military intervention.
General Constantino Chiwenga had challenged 93-year-old President Mugabe after he sacked the vice-president.
Gen Chiwenga said the army was prepared to act to end purges within Mr Mugabe’s Zanu-PF party.
Tensions were raised further on Tuesday when armoured vehicles were seen taking up positions on roads outside Harare, although their purpose was unclear.
Some staff at ZBC were manhandled when soldiers took over their offices in Harare late on Tuesday evening, sources told Reuters.
Workers were told that they “should not worry”, a source added, and that soldiers were only there to protect the site.
The BBC’s Shingai Nyoka, in Harare, said the sounds of heavy gunfire and artillery had been heard in northern suburbs where a number of government officials, including the president, live.
Gunfire was heard near Mr Mugabe’s residence in the suburb of Borrowdale early on Wednesday, a witness told AFP news agency.