HARARE, Zimbabwe  — Giddy with joy and finally free to speak out, vast throngs of demonstrators turned Zimbabwe’s capital into a carnival ground on Saturday in a peaceful outpouring of disdain for President Robert Mugabe and calls for him to quit immediately.

Still clinging to his now-powerless post, the longtime leader was scheduled on Sunday to discuss his expected exit with the military command that put him under house arrest.

People in Harare clambered onto tanks and other military vehicles moving slowly through the crowds, danced around soldiers walking in city streets and surged in the thousands toward the building where Mugabe held official functions, a symbol of the rule of the 93-year-old man who took power after independence from white minority rule in 1980.