French police have broken up a terror ring over the weekend and foiled a planned attack, Interior Minister Bernard Cazeneuve said on Monday.

Seven people of French, Moroccan and Afghan origin and aged from 29 to 37 years, were arrested in all, two in Marseille and most of the others in the eastern city of Strasbourg, he said.

The weekend arrests “enabled us to prevent a long-planned terror attack on our soil,” Cazeneuve told a televised news conference.

“Serious information made these arrests necessary,” a security source told Agence France Presse, asking not to be named because he was not authorized to speak on the case.

One of the world’s oldest and largest Christmas markets is due to open in Strasbourg on Friday. The market attracts tourists from across Europe and was the target of a failed extremist plot in 2000.

Cazeneuve did not say in his declaration to reporters what the target of the would-be attackers was however.

France remains in a state of emergency a year since attacks by ISIS jihadists on Paris which left 130 people dead.

Cazeneuve said 43 people have been arrested in November alone as part of anti-terror operations following deadly ISIS attacks on France over the past two years.