PARIS, 7 June 2003 — French anti-terrorist investigators were yesterday questioning two men — a Moroccan and a German — arrested this week at Charles de Gaulle Airport near Paris on suspicion of membership in extremist groups linked to Al-Qaeda.

Karim Mehdi, 34, who was arrested on Sunday, is suspected of having contacts with the Sept. 11, 2001 hijackers; Christian Ganczarski, 36, who was detained the next day, is believed to have been in liaison with the suicide bomber who blew up a Tunisian synagogue last year.

It was not clear if their arrests were linked.

Mehdi was picked up en route to the French Indian Ocean island of Reunion where investigators say he was planning to reconnoiter for a future terrorist attack on tourist facilities; Ganczarski arrived in Paris after being deported from Saudi Arabia.

But investigators say the two men were known to each other as members of extremist cells in Germany.

Mehdi was placed under judicial investigation Thursday for “criminal conspiracy in relation to terrorist activities,” becoming the first person to be held in France in connection with the Sept. 11 attacks in the United States. Judicial officials said yesterday Ganczarski would be brought before an anti-terrorist judge today.

Magistrate Jean-Louis Bruguiere was expected to place him under investigation in connection with the April 2002 bombing of the synagogue on the Tunisian resort island of Djerba, which killed 21 people.

A German of Polish origin who reverted to Islam and goes by the name Abu Ibrahim, Ganczarski was detained in Germany after the Djerba attack but released for lack of evidence and fled the country. He was detained in Saudi Arabia in late April.

Described by intelligence officials quoted in Le Monde newspaper as “one of the masterminds” of the Tunisia attack, he received a call on his mobile telephone shortly before the blast from the alleged perpetrator Nizar Nawar.

French investigators were likely to focus on any links between Ganczarski and the so-called Hamburg group which is believed to have organized the Sept. 11 attacks — notably its alleged leader Mohammed Atta.

German police who searched his home found the telephone number of the Moroccan Mounir El Motassadeq, who was sentenced by a German court to 15 years in prison in February 2002 for complicity in the US attacks.

Mehdi meanwhile was said by intelligence officials to have had a close relation with Ziad Jarrah, who died on board the aircraft that crashed in Pennsylvania.

Under interrogation Mehdi told French investigators he received training in Afghanistan and Bosnia. In addition to the planned attack in Reunion he spoke of targeting US military bases in Germany, officials said.

“He is more a foot-soldier than anything else, but a foot-soldier to be taken very seriously. He was an all-purpose militant at the service of Al-Qaeda terrorism,” an investigator told AFP.

Mehdi, who has lived in Germany for 14 years, spoke freely to his interrogators but gave little away. “I say anything I like because that’s what I was taught to do. It is the rule in Al-Qaeda to mix up truth and lies,” he was quoted by the investigator as saying.