The brother of one of the jihadists who blew themselves up in the deadly Paris attacks last November was jailed Wednesday for nine years on terror-related charges.

Karim Mohamed-Aggad, whose brother Foued was identified after the November 13 attacks which killed 130 people, was accused of fighting as a jihadist while in Syria between December 2013 and April 2014.

Another six defendants of the so-called Strasbourg group who were in the war-torn country at the same time also received jail terms of six to eight years, of which they must serve two-thirds before having any chance of early release.

The formal charge was criminal association with a view to commit acts of terrorism.

The Paris court also ordered that the defendants, all suspected members of a jihadist cell based in Strasbourg, northeastern France, be added to France's terror watch list.

Francoise Cotta, Mohamed-Aggad's lawyer, said he was considering appealing the sentence.

She said the court had "made a decision based on fear in a France that is afraid".

During the 10 days of hearings in late May and early June, the defendants, now aged between 24 and 27, were anxious to shake off the association with Foued Mohammed-Aggad and the Paris attacks.

They said they returned to France from Syria after witnessing fighting between rebel groups.

They said they had wanted to fight the Syrian regime of Bashar al-Assad and to join their recruiter Mourad Fares but they did not specifically want to join ISIS.

One testified that their trip had no more than a "veneer of religiosity".

At a hearing in May, defense lawyers objected to the prosecutor's decision to use leaked ISIS documents that list the defendants as "combatants".

The documents, acquired by Sky News television in March, include an estimated 173 names of French citizens or residents of France, said a source close the probe, but the defence questioned their authenticity.

Foued Mohamed-Aggad traveled with the same group to Syria but did not return home with them.

Nearly two years later he blew himself up at the Bataclan concert hall in Paris where 90 people were murdered.

Fares was known to French intelligence for recruiting jihadist fighters through social media and the Internet.

Fares -- whom France's Interior Minister Bernard Cazeneuve has described as a "particularly dangerous individual" -- was arrested in August 2014 in Turkey before being handed over to the French authorities.

He is in preventive custody awaiting trial.

AFP contributed to this report