A theme park was among the targets listed by terror suspects arrested in France at the weekend, according to French media.
An area described as having a high number of police officers was also mentioned, iTele reported.
The seven suspects - of French, Moroccan and Afghan origin and aged between 29 and 38 - were detained in the southern port city of Marseilles and the eastern city of Strasbourg overnight on Saturday and Sunday.
The raids followed an eight-month investigation by French security services.
On Monday, interior minister Bernard Cazeneuve told reporters that the arrests prevented "a terrorist act that had been envisaged for a long time on our soil".
Two handguns, an automatic pistol, a machine pistol and jihadist propaganda were found during the raids.
One of the suspects arrested in Strasbourg, named as Yasin B, 38, was an official at a school who went to Syria via Cyprus in 2015, possibly using school holidays to avoid arousing suspicion, iTele said.
During his stay, he and an accomplice, who was also arrested, were taught combat techniques and the art of concealment, the news outlet reported.
Meanwhile, two of those arrested in Marseilles were released on Tuesday.
They had been suspected of helping to shelter a Moroccan identified as Hicham E, who is thought to have financed the group and is still being held by police.
A total of 418 people have been arrested in France for suspected links to terror networks since the start of the year, including 43 people this month alone.
The country remains in a state of emergency a year after Islamic State jihadists killed 130 people in Paris in co-ordinated attacks.