Paris ? French authorities investigating the Sept. 11, 2001, terror attacks in the United States have arrested two men — a Moroccan and a German believed to be a top al-Qaida recruiter — in recent days at the Paris airport, judicial officials said Thursday.

The officials said they believed there was a link between the two suspects.

On Sunday, Karim Mehdi, a 34-year-old Moroccan, was taken into custody at Charles de Gaulle airport in Paris, the officials said on condition of anonymity. He had arrived from Germany and planned to leave to the French island of La Reunion off southeastern Africa.

Under questioning, Mehdi said he was headed to the island to look for tourist sites to attack, along the lines of the October bombing on the Indonesian island of Bali that killed 202 people — mostly foreign tourists, the officials said.

On Monday, Christian Ganczarski was apprehended at the airport and was to appear before an anti-terrorism judge in the coming days, the officials said on condition of anonymity.

Ganczarski also allegedly had links to the April 2002 suicide bombing of a historic synagogue on Tunisia’s tourist island of Djerba that killed 21 people, including 14 German tourists, the officials said.

German authorities allowed Ganczarski to leave the country in December because there was not sufficient evidence to arrest him, German officials said at the time.

Ganczarski was being investigated for suspected membership in a terrorist group after being traced as the recipient of an intercepted phone call from Nizar Naouar, the leading suspect in the Djerba bombing who is believed to have died in the suicide mission.

Mehdi’s arrest was the first in France since French anti-terrorism judges opened an investigation into the Sept. 11 attacks just a few weeks after they took place in 2001.

He appeared before a judge Thursday and was placed under investigation — one step short of being officially charged — for alleged connection with a terrorist enterprise, officials said. He was being held in custody.