PARIS, Jan. 15 (Xinhua) -- A radical islamist who attacked three guards in a jail in northern France last week was presented to an anti-terrorism judge on Monday on charges of assassination attempts in links with terrorist group, news channel BFMTV said.

Christian Ganczarski, a German national of Polish origin converted to Islam, attacked three guards with a pair of scissors and a razor blade at the Vendin-le-Vieil prison.

He is serving an 18-year jail term for his role in an al-Qaida-claimed assault on a synagogue in Tunisia in 2002, which left 21 people killed.

Paris prosecutor office had opened an inquiry for "assassination attempts on persons holding public authority in relation to a terrorist company", according to the report.

Earlier on Monday, hundreds of guards blocked entrance to scores of prisons across France to ask better and secure working conditions.

"Yes, we want security," Jean-Fran?ois Forget, general secretary of the Ufap-Unsa prison union told newschannel BFMTV.

"Radicalized detainees are polluting the entire criminal administration. And those who are there for acts of terrorism or banditry take advantage of this opportunity to further weaken the security of our institutions," he said.

Penitenciary staff suffered between 4,000 and 5,000 000 physical assaults per year, according to Forget.