Thousands march in Zimbabwe against President Robert Mugabe after military put longtime ruler under house arrest

— -- Thousands of Zimbabweans marched through the capital on Saturday demanding that President Robert Mugabe step down, days after the military placed the longtime ruler under house arrest.

Euphoric crowds gathered near the State House where Zimbabweans cheered, danced, waved flags and hugged soldiers who were stationed outside the government building in Harare. Some marchers carried posters and signs, including ones that said, "Enough is enough Mugabe must go" and "Mugabe out."

“It’s like Christmas,” one marcher, Fred Mubay, told The Associated Press.

It was the first public demonstration since Zimbabwe's military apparently took charge earlier in the week, and one that would have been perhaps unthinkable just months ago.

“This is the biggest day in the history of Zimbabwe,” another resident, Trust Chuma, told The Associated Press.

The first signs of a military takeover emerged Tuesday as armored vehicles were deployed near the capital, one week after Mugabe fired his deputy and longtime ally, Vice President Emmerson Mnangagwa, and accused him of scheming to take power, including through witchcraft.

An established Zimbabwean journalist who spoke to ABC News on condition of anonymity said members of the military marched inside the state broadcaster's headquarters on Tuesday and told employees there to not be afraid, that "we are here to protect you" and that they should continue their work as usual.

The U.S. Embassy in Zimbabwe issued an advisory Tuesday night, urging all employees to stay home the following day and warning American citizens in the southern African nation to shelter in place "as a result of the ongoing political uncertainty."

Zimbabwe's army addressed the country on state-run media Wednesday morning, vehemently denying speculation this was a coup d'etat and assuring citizens the president and his family are "safe and sound."

"We are only targeting criminals around him who are committing crimes that are causing social and economic suffering in the country, in order to bring them to justice. As soon as we have accomplished our mission, we expect that the situation will return to normalcy," Maj. Gen. S.B. Moyo, spokesman for the Zimbabwe Defense Forces, said in a statement on the state broadcaster.

"To both our people and the world beyond our borders, we wish to make it abundantly clear that this is not a military takeover of government. What the Zimbabwe Defense Forces is doing is to pacify a degenerating political, social and economic situation in our country, which if not addressed may result in a violent conflict," he added.

Moyo urged other security services to "cooperate" with the army "for the good of the country," and warned that "any provocation will be met with an appropriate response."

As the political turmoil continued to unfold, it remained unclear whether Mugabe was still in power.

The president of neighboring South Africa, Jacob Zuma, said he spoke with Mugabe on Wednesday morning, who told him he was "confined to his home but said that he was fine." Zuma sent "special envoys" to meet with Mugabe and the Zimbabwean army "in light of the unfolding situation," according to a press release from the South African presidency.

The whereabouts of Mugabe's wife were still unknown; though journalists in Harare told ABC News she's believed to be with her husband under house arrest at the presidential palace.

It's uncharted waters for Zimbabweans. Mugabe, 93, has led the country since its independence in 1980. He is the world's oldest head of state. In December last year, Zimbabwe's ruling party ZANU-PF confirmed Mugabe as its sole candidate for the 2018 election, despite concerns over his age and health.

Mugabe is still revered by some Zimbabweans as a freedom fighter who helped liberate the former British colony Rhodesia from white minority rule. But many have come to view him as an avaricious autocrat who has plundered the country's resources.

Zimbabweans have seen the economy expand and contract under Mugabe's reign. In recent years, the economy has suffered from rampant corruption, mounting debt, food shortages, a collapsed currency and a deteriorating investment climate.

The United States in 2003 imposed targeted sanctions, a travel ban and an asset freeze against Mugabe and his close associates, citing the Zimbabwean government's human rights abuses as well as evidence of rigged elections.

Nevertheless, Mugabe so far has showed no signs of relinquishing his iron grip on power. He appeared in public Friday for the first time since the apparent military takeover to preside over a university graduation ceremony in Harare.

The decadeslong ruler is said to be asking for more time amid talks with regional leaders, The Associated Press reported.

Zimbabwe's former war veterans minister, Tshinga Dube, told The Associated Press on Saturday that the ruling party will recall Mugabe "as early as tomorrow."

ABC News' Sohel Uddin contributed to this report.