Egyptian riot police fired tear gas at hundreds of supporters of the country's ousted Islamist president, besieging them inside a prestigious Muslim institution after stone-hurling protesters cut off a main road.
The clashes marked the second day of unrest at Al-Azhar University, Sunni Islam's most prominent centre of learning. Many supporters of ousted President Mohammed Morsi's Muslim Brotherhood are students at Al-Azhar, a stronghold of the group. The campus is also near where Islamists had a sprawling protest camp that security forces raided in August, leaving hundreds dead and sparking days of unrest.
The students' protest started with a march inside campus, where protesters hurled stones at the administrator's offices, smashing windows and breaking doors, said Ibrahim el-Houdhoud, deputy head of the university. He told satellite news channel Al-Jazeera Mubashir Misr that he warned protesters against leaving campus and clashing with security forces.
The protesters however ignored the advice, marching out of the main gates to hold "prayers for the dead" - honouring students killed in earlier clashes between security forces and protesters in July.
The protests come amid heated debate over a new law that would place tougher restrictions on demonstrators, which includes imposing heavy fines and possible jail on violators.
Mr Morsi was overthrown by the military July 3 after millions took to the streets to demand he step down. Since then, Cairo has seen non-stop demonstrations by his supporters demanding his return. A military-backed crackdown has left hundreds dead and seen thousands arrested.
Ousting Mr Morsi escalated militant attacks in Egypt, especially in the volatile Sinai peninsula. Egypt's interior minister escaped an assassination attempt when a car bomb targeted his convoy near his residence in Cairo last month.
Egypt's official news agency MENA reported that two members of Central Security Forces were injured when their bus came under attack near border town of Rafah in northern Sinai. Militants attacked the bus with automatic weapons and fled the scene. The soldiers were heading to their camp in Rafah.