Prominent activist behind Egypt's 2011 uprising, Alaa Abdel-Fattah, jailed for 15 years

A court on Wednesday convicted a prominent activist from Egypt's 2011 uprising for demonstrating without permit and assaulting a policeman, sentencing him to 15 years in prison.

The sentence against Alaa Abdel-Fattah is by far the toughest against any of the liberal, pro-democracy activists behind the 18-day uprising that toppled Hosni Mubarak's 29-year regime. It is also the first conviction of a prominent activist since former army chief Abdel-Fattah el-Sissi took office as president on Sunday.

In the 11 months since el-Sissi ousted the country's first freely elected president, the Muslim Brotherhood's Mohammed Morsi, authorities have launched a massive crackdown on Islamists, detaining at least 16,000 and killing hundreds. That crackdown has overshadowed another, albeit smaller, campaign against secular activists opposed to what they see as the return of Mubarak-era policies.

Security officials said that while Abdel-Fattah was convicted and sentenced in absentia, he did turn up at the Cairo courtroom later on Wednesday and was detained by police. The absentia sentencing means that he now faces an automatic retrial, although in the meantime the conviction stands.

The case against Abdel-Fattah dates back to late last year when he was accused of taking part in an "unauthorized" demonstration against a controversial law that places rigid restrictions on street protests.

According to prosecutors, Abdel-Fattah was accused of taking part in an illegal demonstration, using force to take possession of a two-way radio held by a policeman and blocking traffic.

Twenty-four defendants in the same case were also convicted and sentenced to 15 years in jail.