Police in Cairo have fired tear gas amid another tense standoff with student protesters at al-Azhar University.
The clashes on Sunday came as 21 al-Azhar students were to referred to trial, accused of attacking the headquarters of the Sunni Muslim authority in a November protest and three prominent Egyptian secular activists faced court, charged with participating in a violent protest, following a restrictive new demonstration law.
The case of Ahmed Maher, Ahmed Douma and Mohammed Adel, who is being tried in absentia, is the first of secular activists since former president Mohamed Morsi was deposed by the army in July.
An Al Jazeera correspondent, reporting from Cairo, said police had fired the tear gas at students congregating inside the campus at Azhar Dormitories on Sunday afternoon.
"Dozens of riot police are stationed outside the gate while men dressed in civilian clothes are throwing rocks toward the students," our correspondent said.
A security official said on Sunday that students at the university had hurled rocks at the police and tried to block traffic on a major thoroughfare outside the campus in eastern Cairo.
Student Spokesman Mahmoud Salah said
students had lit a fire at the dorm gates to lessen the impact of tear gas fired by the police.
He said a number of students were injured and that the police fired shotgun pellets. The security agencies always deny using them.
Salah said the police later left the area, and protesters who had taken cover inside the dorm went out to continue their protest.
Our correspondent said the clashes began when police attempted to disperse several hundred students who had been protesting earlier outside the campus.
"They were protesting against the coup and calling for the release of Azharian students detained in the past months and accountability for the death of a medical faculty student in similar clashes that took place at the dorm last month," he said.
Police hold protest
Egyptian police rallied themselves later on Sunday to demand higher wages, in a rare act of defiance of the
new protest law which they have been enforcing.
About 200 non-commissioned officers had been granted permission to protest at a police club in Cairo, where they called on officials to come to discuss their pay demand with them.
When they received no response they marched to the Interior Ministry in defiance of the new law.
Security sources said they shoved barricades at fellow members of the security forces outside the club, before the protesters were allowed to march.
A court has already sentenced 12 Azharian student demonstrators to 17 years in jail for violence during another protest.
The Cairo court on Sunday adjourned the case of the three activists accused of charges including assaulting police officers and joining a protest without seeking a police permit as required by a new law.
Both Maher, the founder of the April 6 youth movement that led the 2011 revolt against Hosni Mubarak, and Douma denied the accusations.
"We will pursue our struggle inside and outside (the prison), the authority which is using the judiciary to put us in jail will fall," Douma said.
The court is due to deliver its verdict on December 22.