PARIS (AP) — French police have detained three people, including a soldier, in southern France as part of an investigation into last year’s deadly terror attacks in Toulouse that targeted Jews and paratroopers, prosecutors said Wednesday.

They were detained about 10 days after President Francois Hollande, speaking in Toulouse, said France is tightening its intelligence-gathering to prevent further terror attacks like those committed by Mohamed Merah, who police say killed three Jewish schoolchildren, a rabbi and three paratroopers last March. Merah was later killed in a shootout with police.

Two people in their early 20s were arrested late Tuesday in Toulouse, one in the gritty Les Izards neighborhood where Merah, a radical Muslim, spent part of his childhood. A third person, a soldier on active duty, was arrested Wednesday morning in the nearby town of Castres, prosecutors’ spokeswoman Agnes Thibault-Lecuivre said. A paratrooper regiment is based in Castres.

She described all three as being close to Merah, but said investigators want to know exactly what those relationships were, and whether any of the three could have had a role in preparing the attacks.

Investigators are trying to understand how Merah managed to carry out the attacks, “both intellectually and materially,” and whether any of the three may have had a role at some level, Thibault-Lecuivre said.

Five people had been detained earlier, but all freed after questioning. Only Merah’s brother, Abdelkader, has been charged with complicity in the case and is being held.

In France, authorities have four days to question a suspect before either filing preliminary charges or letting the person go.

Copyright 2013 The Associated Press.