Riot police protect the university

Al-Azhar University is the most prestigious institution for mainstream Sunni Muslims, attracting students from around the world.

Riot police were deployed around the university on Tuesday, but no disturbances were reported. The students demanded Mr Hosni's resignation for allowing the book to be published.

Intellectuals have defended the book, accusing the Islamists of inciting violence.

Clashes worst in years

The clashes were amongst the worst in Cairo since the protests against the Gulf War in 1991.

Students, shouting religious slogans, pelted police with stones from behind the fence of the university buildings.

The police shot back with teargas and rubber bullets as the protests grew increasingly violent.

Ten cars and two buses were reportedly damaged in the exchanges.

Several protesters were badly injured

The book that triggered this protest, first published in Beirut in 1983, was released in Egypt in November by an institution affiliated with the Culture Ministry.

The novel's plot centers on two leftist Iraqi intellectuals who fled the injustice of Iraqi President Saddam Hussein in the late 1970s.

The characters blame political oppression in the Arab world on dictatorships and conservative movements.

In one of the most controversial extracts God is described as a failed artist.