Zimbabwe’s beleaguered President Robert Mugabe attended a graduation ceremony at a university in the capital Harare on Friday, his first public appearance since he was put under house arrest by the army late Tuesday.

The 93-year-old wore a graduation gown and cap for the ceremony, at the Zimbabwe Open University.

It came as the country’s army said it has made “significant progress” in their “operation” after seizing control of state television and the capital’s airport during an apparent coup earlier this week. Mugabe, the world’s oldest head of state, refused to stand down during a meeting with military officials Thursday, AFP reported.

Reuters, citing a source within the ruling Zanu-PF party, said the party was due to draft a motion to fire Mugabe on Sunday and that if he still refused to stand down, there were plans to to impeach him on Tuesday.

In a statement Friday, the Zimbabwe Defence Forces (ZDF) said “they are currently engaging with the Commander-in-Chief, President Mugabe, on the way forward and will advise the nation of the outcome as soon as is possible,” the state-run broadcaster Zimbabwe Broadcasting Corporation (ZBC) reported.

The military commended the public “for remaining patient and peaceful as they carry out the operation,” according to the statement.

Army troops and armored vehicles continued to patrol Harare on Friday.

The army announced Wednesday that it detained Mugabe, 93 — who has ruled the country for 37 years — and his wife Grace, 52. The military denied staging a coup and said “normalcy” would soon return after it completed its “mission” of rooting out “criminals” who were targeting the nation’s leader.

The catalyst for the takeover was the firing last week of Vice President Emmerson Mnangagwa, who Mugabe accused of plotting to take over from him. Mnangagwa, a former defense minister who has strong support within the military, fled to South Africa.

Mugabe has ruled the country since independence from minority white rule in 1980. Grace Mugabe was expected to be appointed vice president by Zanu-PF in December and was the favorite to succeed her husband. Grace Mugabe and Mnangagwa’s factions within the party had been battling for dominance before Mnangagwa was fired.