HARARE, Zimbabwe — A day after the Zimbabwean Army detained President Robert Mugabe, representatives of South Africa and the Roman Catholic Church on Thursday sought to defuse the crisis in closed-door negotiations aimed at producing some kind of transitional settlement.
President Jacob G. Zuma of South Africa told lawmakers in his own country that the situation “very shortly will be coming clear,” as an array of activist groups and political opponents of Mr. Mugabe urged him to step aside peacefully.
Feeling their way through uncharted territory after the military placed Mr.Mugabe under house arrest, Zimbabweans ventured into streets patrolled by armored vehicles and awaited some kind of signal of what a new era might bring.
Many in this country of 16 million people have known no president other than the 93-year-old Mr. Mugabe, a onetime leader of the country’s anticolonial struggle who traded the liberator’s mantle for the iron fist as one of Africa’s most enduring autocrats.
Early Wednesday, the military announced that soldiers had confined Mr. Mugabe and his flamboyant and ambitious wife, Grace Mugabe, to their home.
In photos released by state-run news outlets in Zimbabwe, Mr. Mugabe can be seen meeting with South African envoys and Constantine Chiwenga, general commander of the Zimbabwe Defense Forces. In one, he can be seen shaking hands with Mr. Chiwenga and smiling.
His wife is not shown in any of the photos, leaving some to speculate where she might be.
While the military denied that a coup was underway, its actions signaled clearly that Mr. Mugabe no longer exercised supreme power. However, it remained unclear who would replace Mr. Mugabe even if he agreed to step down — possibly at a congress in December of his ruling ZANU-PF party.
The potential successor mentioned most frequently is Emmerson Mnangagwa, a close Mugabe ally for decades until Mr. Mugabe dismissed him as vice president. That action prompted Mr. Mnangagwa to flee to South Africa last week, and it was not clear whether he has since returned to Zimbabwe. Another issue is the future of Mrs. Mugabe, whom Mr. Mugabe had seemed to promote over Mr. Mnangagwa, precipitating the current crisis.
One opposition leader, Morgan Tsvangirai, who served as prime minister during a power-sharing government between 2009 and 2013, called on Mr. Mugabe to step down “in the interest of the people.”
The streets of the capital seemed calm on Thursday, but some residents said they detected muted anticipation of change. There were no signs of arrests or violence, but soldiers in camouflage lounged on armored personnel carriers mounted with machine guns, and a lone fighter jet roared above, its mission unclear.
The military’s action has sent shock waves around the region. The Southern African Development Community, a regional bloc that includes Zimbabwe, met on Thursday in Gaborone, Botswana, to discuss the seeming slow-motion coup and the apparent impasse that has flowed from it.
In a statement issued later in the day, the bloc urged peace and called for an urgent meeting of the group to discuss the crisis.
As fevered speculation swept the capital, Reuters reported on Thursday that Mr. Mugabe was resisting pressure to join some kind of transitional arrangement that would embrace opposition leaders.
With a blend of guile and brutality, Mr. Mugabe has led Zimbabwe since its independence from Britain in 1980. In that period, the country’s once-thriving economy has crumbled into widespread joblessness and deprivation, forcing many into an informal economy of street vendors and traders.
Mr. Mugabe’s trump card in negotiations is likely to be a broad reluctance among regional and Zimbabwean leaders to embark on a new era as a direct result of a coup.
“I think he will play hardball,” Ibbo Mandaza, an author, academic and publisher, said in a telephone interview.
Reuters also reported that Mr. Mugabe insisted on remaining in office until the completion of his term next year. Mr. Mandaza predicted that he would probably try to focus negotiations on the restoration of constitutional rule and on the military’s return to its barracks.
“I think people are trying to get away from the coup situation,” Mr. Mandaza said. “My own feeling is that these negotiations will be protracted,” and that Zimbabwe’s immediate future will be “very uneasy and very uncomfortable.”