France's top security official says authorities have turned away more than 18,000 people at the country's borders for security reasons since extremist attacks in November.

Interior Minister Bernard Cazeneuve said borders will be strictly watched during the European soccer championship, hosted in 10 French cities June 10-July 10.

A security official said the 18,000 were turned away based on intelligence or suspicious documents amid some 32 million border checks since the Nov. 13 attacks. The official, not authorized to be publicly named, did not say where the people were sent or how many of them were arrested.

France reinforced its borders after the attacks, which killed 130, and remains in a state of emergency.

Border security is a sensitive issue among the 26 countries in Europe's travel-free zone.