CAIRO — Riot police officers fired tear gas at students at Egypt’s main Islamic university on Saturday in a clash that left one protester dead and an administration building in flames, officials and student

The police said they had entered the eastern Cairo campus of Al-Azhar University, the site of frequent clashes in recent weeks, because students were disrupting end-of-semester exams. They said they had also deployed around other Egyptian universities to prevent supporters of the ousted president, Mohamed Morsi, from intimidating other students trying to take the tests.

Morsi supporters have called for a boycott of exams but deny government claims that they threatened anyone.

For weeks, students at Al-Azhar, a stronghold of Morsi supporters, have been protesting his ouster and a subsequent state crackdown against the Muslim Brotherhood, the movement he once led. Last week, the government declared the Brotherhood a terrorist organization.

University professors and security officials accused students on Saturday of blocking entrances to classroom buildings and harassing students as they made their way onto campus.

A statement from the Interior Ministry, which is in charge of the police, said students had stormed several buildings on campus to “terrorize students and faculty.” It said some had fired shotguns into the air and smashed furniture.

The ministry statement said the attack had prompted the police to move in to disperse the crowd, leading the students to set the Faculty of Commerce building on fire.

Aya Fathy, a student spokeswoman, disputed the official claim, saying the students were protesting peacefully. She said the police had moved in to break up protesters outside the faculty building, firing indiscriminately and killing one student, identified as Khaled el-Haddad.

She accused the police of setting the building on fire to blame the students and said the police force was chasing students on campus.

The Interior Ministry did not mention the death of Mr. Haddad in its statement, but a security official confirmed that he had been killed and said 14 others had been injured.