Security forces fired teargas to disperse hundreds of students protesting against Egypt's military-installed government at Cairo's al-Azhar university on Monday, a week before ousted Islamist President Mohamed Mursi is due to face trial.
Mursi, who has been detained since the army overthrew him on July 3, is expected to go on trial next Monday on charges of inciting murder. His supporters have called for mass protests on that day, raising the prospect of more violence as Egypt's political crisis continues.
The students chanted "down with military rule" before the security forces moved in to break up the protest.
Repeated student demonstrations demanding Mursi's return are a delicate matter for the authorities because the administration at al-Azhar, the ancient seat of Sunni Muslim learning, has historically toed the government line.
Monday's protest, like several this month, took place near the Rabaa al-Adawiya mosque, where security forces dispersed a large pro-Mursi protest camp on August 14, killing hundreds.
Thousands of Islamist supporters and leaders of Mursi's Muslim Brotherhood have also been jailed since his overthrow and the movement has been banned.
Mursi's supporters say his removal was a coup against a freely elected leader. The army says it was responding to the will of the people, who had taken to the streets to protest against his rule.
Interim President Adly Mansour was quoted by the state news agency as saying in a meeting with General Abdel Fattah al-Sisi, the army chief who toppled Mursi, and the interior minister that "imposing security was the main priority at this important stage".
Since Mursi's overthrow, attacks by Islamist militants have increased, particularly against police and soldiers in the Sinai Peninsula, which borders Israel.