Islamist students at Egypt's Al-Azhar University in Cairo and Mansoura defied on Sunday a recently imposed ban targeting on-campus protests, while some at the turbulent institution called for a strike.

Dozens of students across several faculties at Al-Azhar, the highest seat of Sunni Islam learning, protested around the university's main administrative building and at the headquarters of their respective faculties, calling for a halt to studies until "justice" for a fellow student killed last week is fulfilled, Al-Ahram's Arabic news website reported.

Vice president of the university's Tanta branch, Ahmed Hosni, told Ahram that studies proceeded normally on campuses in Cairo and other governorates, noting that the university's "students did not respond to a call by a minority."

Protesters held aloft banners prompting students to strike and others declaring "We won't give up their right," in reference to their recently slain colleague and the scores arrested during the unrest that followed the ouster of Islamist president Mohamed Morsi.

A student supporter of Morsi was shot dead during clashes with security forces on Wednesday before police stormed the campus as violence flared. At least 16 students were arrested.

On Wednesday, hundreds of students had roamed the campus in Cairo's northeastern Nasr City district shouting anti-police and anti-army slogans.

Hundreds of students supporting Morsi's Muslim Brotherhood movement also reportedly protested Sunday on the Nile Delta's Al-Mansoura campus to mark 100 days since a mid-August deadly police raid on two pro-Morsi protest camps in Cairo left hundreds dead.

The protests come days after the administration banned on-campus protests and suspended student union activity in response to the turmoil sweeping the university. It also called in police to guard its buildings and intervene when necessary to quell student unrest.

University Head Osama El-Abd has reiterated warnings that he would firmly confront any breaches of the decision.

Prompted by nationwide mass protests, Egypt's army deposed Morsi on 3 July. Authorities have since cracked down on Islamists, arresting thousands.

The 1000-year-old institution had given its blessings to Morsi's ouster and has since been in lockstep with interim leaders, infuriating Morsi's Islamist backers and prompting students to call for the removal of El-Abd as well as Grand Imam Ahmed El-Tayeb, Al-Azhar's highest authority.

Violent protests in October prompted police to enter the university campus for the first time since a 2010 court ruling barred Interior Ministry personnel from university grounds. The move has heightened fears of renewed heavy-handed security practices on student activism.

Dozens of Al-Azhar students have been handed jail sentences for "stirring riots."