Zimbabweans are waiting to see what steps the military will take next after seizing control of the country.
President Robert Mugabe is said to be under house arrest but the whereabouts of his wife grace, who was bidding to succeed him as president, are unknown.
South African Ministers have been in the capital Harare meeting the army and political parties.
The Southern African Development Community (SADC) regional bloc will hold emergency talks on Thursday.
Tensions were raised further on Monday when Army Chief General Constantino Chiwenga said the army was prepared to act to end purges within Zanu-PF.
General Chiwenga is a close ally of sacked Vice President, Emmerson Mnangagwa and both are veterans of the 1970s war which ended white minority rule.
A Zimbabwean opposition leader, Tendai Biti, told the BBC he wanted to see a transitional authority in place.
“It is urgent that we go back to democracy. It is urgent that we go back to legitimacy but we need a transitional period and I think, I hope, that dialogue can now be opened between the army and Zimbabweans,” he said.
He later told Reuters that he would join a national unity government if Morgan Tsvangirai, head of the Movement for Democratic Change-Tsvangirai (MDC-T) party, was also in it.