CAIRO – A prominent Egyptian blogger jailed for four years for writings deemed insulting to Islam and for calling President Hosni Mubarak "a symbol of tyranny" has been released, his brother said Wednesday.

Abdel Kareem Nabil was the first blogger in Egypt convicted specifically for his writings in a case that government critics said was intended to serve as a warning to others.

His prosecution was part of a government crackdown on bloggers and media outlets and drew a flood of condemnation from international and Egyptian rights groups.

He was released Monday after being held 10 days beyond the end of his sentence without explanation, said his brother, Abdel Rahman. The Cairo-based Arabic Network for Human Rights Information said last week that during that time he was subjected to repeated beatings by an officer at the State Security Investigation office in Alexandria.

His brother said Wednesday that Nabil needed a rest before talking to media and that the family was not yet prepared to release a statement.

Nabil, who wrote under the name Kareem Amer, was an unusually scathing critic of conservative Muslims.

Much of his criticism was directed at Cairo's Al-Azhar University, the pre-eminent institution of religious thought in Sunni Islam, where he was studying law.

He denounced the school as "the university of terrorism," accusing it of promoting radical ideas and suppressing free thought. Al-Azhar "stuffs its students' brains and turns them into human beasts ... teaching them that there is not place for differences in this life," he wrote.

In other writings, he called Al-Azhar the "other face of the coin of al-Qaida" and called for the university to be dissolved or turned into a secular institution.

His frequent attacks on Al-Azhar led the university to expel him and then push prosecutors to bring him to trial.

The judge in his trial said Nabil also insulted the Prophet Muhammad with a piece he wrote in 2005 after riots in which angry Muslim worshippers attacked a Coptic Christian church over a play deemed offensive to Islam.

"Muslims revealed their true ugly face and appeared to all the world that they are full of brutality, barbarism and inhumanity," Nabil wrote in his blog. He called Muhammad and his seventh century followers "spillers of blood" for their teachings on warfare — a comment cited by the judge.

In a later essay not cited by the court, Nabil sought to clarify his comments, saying Muhammad was "great" but that his teachings on warfare and other issues should be viewed as a product of their time.