The University of Zimbabwe postponed exams on Monday after students started chanting and singing songs against 93-year-old President Robert Mugabe. Picture: AP Photo/Tsvangirayi Mukwazhi, File

Harare - The University of Zimbabwe postponed exams on Monday after students started chanting and singing songs against 93-year-old President Robert Mugabe, who is under mounting pressure to resign, a Reuters witness said.

According to social media, the students are calling on Grace Mugabe's PhD to be withdrawn and the university's vice chancellor Nyagura to resign.

Students have also promised to boycott writing examinations which were scheduled to start on Monday until Mugabe announces his resignation

Examinations have been deferred 'until further notice.'

The 93-year-old president defied expectations that he would resign in a national address on Sunday night during which he was flanked by military generals. 

Instead, Mugabe stressed that he was still in power and would preside over the upcoming Zanu-PF elective conference.

Zanu-PF has given Mugabe less than 24 hours to quit as head of state or face impeachment.

Reuters and IOL