Authorities in France have arrested seven men and say they have foiled a terror plot which was ‘‘envisaged for some time.’‘

Bernard Cazeneuve, the country’s Interior Minister, did not reveal the site of the planned attack.

“An anti-terrorist operation led by the General Directorate for Internal Security (GDIS – intelligence services) under the authority of the judiciary took place overnight between Saturday and Sunday in Marseille and Strasbourg. It led to the arrest of seven people, aged between 29 and 37, of French, Moroccan and Afghan nationalities,” Cazeneuve said.

Most of the arrested suspects are said to have come from Strasbourg, but the city and its famous Christmas market are not reported to have been the target of the planned attack.

Despite that, Strasbourg’s Mayor Roland Ries said security around the market would be tightened for the festive period.

France remains in a state of emergency, giving extra powers to police and security forces, following last year’s Paris attacks which left 130 people dead.