Zimbabwe's President Robert Mugabe addresses supporters gathered to celebrate his 92nd birthday in Masvingo February 27, 2016. ? Reuters

HARARE: Zimbabwe's ruling ZANU-PF party said on Sunday that Robert Mugabe must resign as the country's president or face impeachment, as it also resolved to expel his wife Grace.

A party meeting in Harare agreed that "Mugabe resign forthwith from his position as president of Zimbabwe" by midday Monday or face impeachment proceedings.

Party spokesman Simon Khaya Moyo added that "Grace is on the list of people to be expelled from the party".

Mugabe's grip on power was broken last week when the military took over, angered at his wife Grace's emergence as the leading candidate to succeed the 93-year-old president.

On Saturday, tens of thousands of overjoyed demonstrators flooded the streets of Zimbabwe in peaceful celebrations marking the apparent end of his long and authoritarian rule.