Cairo: US-based Human Rights Watch urged Egypt on Saturday to free a blogger on trial over writings that prosecutors claim defame Islam and insult President Hosni Mubarak.

Abdel Kareem Nabil Suleiman has been detained since November and is the first person to stand trial in Egypt over writings posted on the internet.

Rights groups say they fear a conviction may set a legal precedent limiting internet freedom in Egypt. Suleiman could face up to nine years in jail if convicted.

"By curbing a blogger's freedom to post, the government may be trying to close an important space for Egyptians to speak openly about events and issues that worry them," said Sarah Leah Whitson, director for Human Rights Watch.

"The Egyptian government should immediately drop all charges against Suleiman and release him," she added.

Suleiman, a Muslim and a liberal, has not denied writing the articles but said they merely represented his views.

He has slammed Mubarak in his blogs, comparing him to the dictatorial pharaohs who ruled ancient Egypt. In another blog, he accused Muslims of savagery in 2005.

Other opposition bloggers have also been arrested periodically. Last year, Reporters Without Borders added Egypt to the list of worst suppressors of freedom on the net.